4.1 Nature of Living Matter, ‘Elan Vital’
If we consider the milieu as the stage of the life drama (Lotka), the living beings are the actors and the drama consists, like any proper ‘roman familial’, “of the relation between these actors with their environment and with another.”1 If we want to consider living things from this point of view, we are much more concerned with their activities and with their composition as with their form. Our problem is, therefore, chiefly a physiological one. Most living beings have, somewhere in this milieu, a certain area in which their development, their increase, their general well being is optimal. Toward the limits of the milieu this “vitality” may be decreased or lead into other vegetative channels. It is probable that in certain cases sexual reproduction is all but a luxuriance phenomenon. Many are the cases described in the literature where copious fruiting or flowering are immediately preceded the death of the organism in question. In order to obtain large quantities of variants of a given species, the birth rate, the natality, should be high; the death rate, the mortality should be lowest. Birth rate and death rate, although both influenced by internal as well as by external factors, show a certain contrast; natality being chiefly influenced by the milieu interne, while the mortality is shaped chiefly by the outward environment. In this section we shall therefore, deal with population growth.
4.1.2 Method of increase
We have growth, we have vegetative and sexual reproduction. In any case, there is increase in living mass. Behind this increase there appears a blind driving force, a veritable life force, an ‘élan vital’. This force of course has nothing in common but the name with its physical counterpart, but it is an enormous urge which presses every living thing to procreate, to make more of its self sameness, as if its specific protoplasm were the very salt of the earth, and the only species worthy to fill the earth. Give any organism its chance, and it will push all others aside. Any person with imagination shudders when he sees the amorphous masses of yeast cultured from a few cells in a few hours in the brewery, and our urge, to fill the earth with man, seems much less divine and less human than it was before, may be our deepest protoplasmic urge, which we have in common with all other living creatures.2
4.1.3 Laws of increase
We shall have occasion later to revert to the problem of population curves (Section 5.1, Growth Curve). In the majority of cases in time x there is an S-shaped increase in the population y, which reaches a saturation level a (Fig. 4.1). This has been represented (arbitrarily as we shall see) by many authors as
The first phase, before the inflection point I is reached, is called the logarithmic phase (especially by bacteriologists), and it is this phase often preceded by a lag phase, that often represents growth. This may be represented by a simple e function or a parabola, often of higher degree.
In the above equation the point of inflection at x = 0 is symmetrical at y = a/2. However, in practice the first, or the second point of the curve may be the shortest. Moreover, after reaching the limit a, there may be superposition of new S-curves, or there may be a decrease. We shall see later that the growth of a filamentous algae, or of unicellulars in which the milieu is kept constant, often follows a curious law; a series of S-curves which, together, are situated on a parabola (Fig. 4.2). For epidemiology the shape of such curves is of great importance. It often looks like the figure below (Fig. 4.3). The section on population statistics the matter shall be dealt with more in full.3
4.1.4 Census of populations (e.g., birds)
L. Tinbergen has given a census of our common Holland birds.4 It appears that their numbers are to all intents and purposes, stationary. Mortality and natality keeping each other in check. The population curve would probably look somewhat like in Figure 4.4.
From the literature we should cull data on 1) species, 2) species periodically reduced to one individual (in winter), and 3) species subject to “vital explosions” (Lotka?).5 This section should be elaborated. In laboratory populations (bacteria), we usually obtain increase curves of the following shape (y axis, Bacillus megaterium). Here secondary and tertiary masses appear (Fig. 4.5). The whole phenomenon is highly influenced by milieu.
4.1.5 Natural sequence
A sequence (see Section 7.8, Cycles) may either involve the life cycle of one organism or of several. In the first case the culture may show considerable “lag” (Pasteur effect, mildew in yeast) then a logarithmic phase sets in. Somewhere in this phase (as in the case of Chlamydomonas) substances are found that induce sexual activity, and so the culture will go through its developmental phase. It makes its own “necrosymbiotic” milieu.6 If other organisms enter in (the case is even more complicated), their influence, adverse or beneficial, belongs to the external milieu (see Section 4.5) and is, like the “necrosymbiosis” chiefly chemical. On totally sterile soil, perfectly mineral, we have to expect first a perfect, nitrogen fixing, autotroph, to be followed by these organisms that are less independent. In the case of epidemics (Sections 5.10 and 7.5) the epiparasite and the phage may come in as a natural brake.
4.1.6 Equilibrium conditions
Equilibrium conditions are of the nature of the stationary state (or “harmony” as it is called by my fellow country man J. Straub).7 This is a condition in which the “same” is maintained by a continuous change, like the shape of a water jet from a faucet. Now in nature such a monotonous pressure is never realised. There is a “drift” in the equilibrium, in the stationary state. This drift is not undisturbed, it appears as a life cycle, as a biocoenotic cycle, it is recurrent. Lao Tze has said: ”One engendered many, many engendered millions - and a million things return to one.” Still, apparently constant conditions may be obtained in laboratory cultures, although we should never forget the diction of Winogradsky, that we are working, in this case, with ‘circus animals.’
4.1.7 List of organisms of geochemical importance
(This to be elaborated to a separate section, with plates and descriptions).
4.2 Chemical Composition
In 1898 Léo Erréra of Brussels published a memoir entitled Pourquoi les Elements Vivants ont-ils des Composés Moléculaires Moins Elevés.8
4.2.1 Relation between common and bioelements
[Baas Becking left this section blank.]
4.2.2 Analysis of plants
Nothing seems more variable than ash analysis of vegetables.
4.2.3 Analysis of animals
[Baas Becking left this section blank.]
4.2.4 Comparison of anomalous cases; accumulations by certain organisms
Al(OH)3, accumulated by Lycopods and by Symplocos a tropical tree (family Symplocaceae) the extract of the leaves being used by the natives as a mordant.
SiO2 in special cells (stegmata) of grasses, also in horsetails. In the internodes of the bamboo in in porous like, very light masses, “tabashir.” Further in radiolarian and diatom shells in sponge spicules
CaCO3, Moracaea (Cystolith) and Urticularia in general. In the leaves of Petraea (Verbenaceae). In the walls of coralline algae (Corallina, Amphiroa, Lithophyllium, Lithothamnion) and green algae like Halimeda, freshwater algae like Chara. Also, calcite, aragonite, dolomite in many shells.9
Apatite Ca5F(PO4)3, occurs in phosphate rock, in guano also Ca5Cl(PO4)3. Further as calcite and Cu3 (PO4)2CaCO3. H2O, collophane Ca5(PO4)2.5(CO3)0.5(OH) and vivianite Fe3P2O8H2. Iodine and potash accumulate in sponges, in brown and in red algae. Bromine chiefly in red algae.
KH2PO4, accumulated as well as dissipated by every living cell. Excrement (“night-soil” of the Chinese) very much in KH2PO4.
4.2.5 Milieu externe and milieu interne
4.2.5.a Salt intake and excretion, secretion and recretion
We shall here only briefly outline the problem of intake and production of substances by living cells as part of the relation between milieu externe and milieu interne. The mechanism of the intake of substances is still obscure. Size of molecule, solubility in fat solvents and electric charge each playing a role. Moreover, the entrance of many substances in the cell requires energy (‘das anionen phenomenon’).10 Arisz (1943) has analysed the mechanism of intake of various organic compounds.11
The substances entering may be given off again without change (Fig. 4.6). This we name recretion. A case in point is KH2PO4 (Loosjes, Lausberg) which is one of the most mobile substances both in animal and in plant physiology.12 Furthermore, the entering substances may be changed in metabolism and, as important metabolite, still be given off to the milieu externe. This is called secretion, for instance of sugars in plants as nectarines, or milk in mammals. Finally, waste products may be excreted. In the sulphur bacteria, which dehydrogenate H2S the sulphur may be formed intra- or extracellular (endo- and ectothiobacteria). Here it serves in both cases as substrate for further dehydrogenases. The above classification apparently breaks down (Frey-Wyssling;13 Baas Becking, 1924b). It seems impossible to enumerate the substances given off by living cells. A few cases will be mentioned in the section on symbiosis. The milieu therefore receives;
a) concentrates by respiration
b) substances of high energy potential by secretion and
c) special substances by excretion.
When the organism dies it yields its materials to the cyclic changes further described in the following sections.
4.2.5.b Temperature regulation
Heart regulation in poikilothermic animals is partly performed by increased respiration, partly by increased evaporation. As the heat of evaporation of water is high (580 cal/cm3 at room temp.) great quantities of heat may be removed this way. A green leaf which absorbs ±7% of the incident radiation can be heated up in a short time to 70 °C if transpiration is prevented by coating the leaf surface with oil. The natural leaf surface behaves as a free water surface (law of linear dimensions of pores; Brown and Escombe, 1900), and in such a way, through evaporation, may maintain a temperature within the physiological range. On a sunny day at our latitude a leaf may receive 0.8 cal/cm2/minute, absorbing 0.6 cal/cm2/minute or in an 8 hour sunny day 8 × 60 × 0.6= 288 cal/cm2. A free water surface will evaporate on such a day about 0.6 M or consuming per cm2 0.6 × 580 cal = ±350 calories/cm2. As the two results show the same order of magnitude it will be seen that the leaf does not need to become much warmer than the surroundings. It will, at the same time, supply the atmosphere with much water.
[In the margin Baas Becking added:] A large beach tree has a leaf surface of 1.00 × 106 cm2 it would contribute 600,000 kg of water on one sunny day.
4.2.6 Summary and conclusions
There is a continuous give and take between the organism and its environment. This exchange lies at the base of geobiology. Apart from a chemical, and a physical instance of this exchange cited above, Sections 5, 6 and 7 deal with this matter more fully. But before dealing with these problems, it has to be stated specifically that organisms are in continuous interchange with their environment, a fact, apparently sometimes forgotten in laboratory and museum sciences. “Integer vitae” (when applied to material life) is a contradictio in terminis. Life is continuous interference of the milieu by life and of life by the milieu. Only a dried or stuffed specimen, sufficiently preserved, does not show such a relation. But then, it isn’t alive anymore. Here also decision whether a process is due to milieu extern or due to milieu intern (leaves of Canavalia, Kleinhoonte and Brouwer, 1925).14
Stones as large as man’s fist have blown across the Sahara (Rohlf) and Gobi (Przhewalsky).15
Fall of lichens was reported in Persia by de Candolle.16
Deflation uniform upward in current will keep suspended quartz grains (Thoulet, 1908a and b).
|Vm m/sec .||𝜙 quartz in mm .|
|Vm m/sec .||𝜙 quartz in mm .|
|Distance, Gravel||a few feet|
|Conc sand 1-0.25 mm||several rods|
|Fine sand (0.25-0.125 mm)||less than a mile|
|Course dust (0.0625-0.03125 mm)||200 miles|
|Medium dust (0.03-0.015 mm)||1000 miles|
|Very fine dust||across the globe|
|Distance, Gravel||a few feet|
|Conc sand 1-0.25 mm||several rods|
|Fine sand (0.25-0.125 mm)||less than a mile|
|Course dust (0.0625-0.03125 mm)||200 miles|
|Medium dust (0.03-0.015 mm)||1000 miles|
|Very fine dust||across the globe|
April 1892 yellow China dust on deck ship West South of Nagasaki, at least 1000 miles distant.19 Australia dust reaches New Zealand over 1500 miles. Sahara dust N. Germany. Dust rain Canary Islands, volume almost 4 × 106 m3, 5 mm per century.
4.3 Distribution, Cosmopolitans, Physical Causes
There is interplanetary distribution as well as terrestrial distribution to be considered. According to Lebedev, organisms should travel, once sufficiently outside the gravitational field, by radiation pressure.20 Svante Arrhenius has actually suggested such a distribution. It remains to be seen whether any organism, even capsulated and dehydrated, could withstand the enormous intensities of ultraviolet radiation! Charles B. Lipman, in 1929, claimed to have isolated “very large” bacteria from a meteorite.21 Dr. C.B. van Niel and the author had occasion to examine some of his cultures. They looked very much like Bacillus megatherium again! That these bacteria should come from the meteorite seems, at the least, improbable. Remaining for the moment, upon the earth, we shall consider the various methods of distribution of organisms over the surface of this planet in order to find the foundations of the cosmopolitan distribution of so many forms. It will appear that, below a certain critical size (see Fig. 4.7) the air is the universal medium of transport.22 The other media, water and animate agents are, for microbes, decidedly of secondary importance. For higher organisms, however, there appear impediments to distribution, which cause the organisms to occur in certain, more or less defined areas. The area concept shall be dealt with briefly. See also [Dispersal of ashes after eruption of Mount Katmai, southern Alaska in 1912] Correns, p. 159.
On the accompanying Table 4.3 the relative size of various organisms is given, on a logarithmic scale, in relation to that of the electron and of the light year. (10-10 – 10+17 cm). Man, the measure of all things, has a central position in this explored universe. Organisms range from 10-6 – 10+4 cm. Air borne are organisms may be when sufficiently small. But the diagram given is misleading. According to this diagram, a minimum velocity of 100 m/sec, a veritable gale, should be required to carry a particle of 20μ radius. Now we know of many larger particles carried by air. They are probably lifted by an intense vertical air current, such as we find in storm clouds (cumuli) or in dust devils (the “pillar of cloud” of the Old Testament,23 called ‘willie-willie’ in Australia).24 Also the ascending air masses above volcanoes drag upwards huge masses of dust. Of course, an eruption may even contribute much more. (see Royal Soc. Report on Krakatoa, and the report of Verbeek and Ferzenaar).25 It is not improbable that very large objects may be transported this way. Even fishes, turtles, frogs are known to have “fallen from Heaven.” Granted the possibility of transport to considerable levels (say 10 km) the question remains what distance may be travelled before the particles settle down again. In practice, the particles should be not much longer as ϕ = 10-2 cm = 0.1 mm = 100μ.
4.3.3 Experiment of Louis Pasteur
It is said that the Chinese had a vague notion of the fact that infection diseases might be carried by air. During an epidemic the air was kept “moving” by noises made on luytes [lutes] and drums. A. v. Leeuwenhoeck (1682-1723) already fully recognised the importance of air transport and mentions it in his “Sendbrieven” at several places.26 The father of protozoology, Ehrenberg, was convinced of the great importance of air transport of protozoa.27 Darwin, at several places in his works, mentions the great influence such transport may have on the distribution of organisms.28 It was left to Pasteur, in the course of his classic tilt on the subject of spontaneous generations, to prove, experimentally in a classic research the presence of organisms in the air (citations should be given from the original) (see Fig. 4.8). One of the early (1861) experiments shall be mentioned here in short. Outside air (w) was sucked through a tube filled with gum cotton (g) by means of a water pump. After several hours of suction, the gum cotton was dissolved in ether and the residue microscopised. Moulds, spores and yeasts were observed. Molisch coined the word “aeroplankton” for the organisms he observed sticking to slides moistened with glycerol.
4.3.3.a Wind transport of higher organisms
Amongst the higher organisms there are those fit for wind transport. Feekes, working on the dispersal of plants in the newly won Zuyderzee polders (Feekes, 1936) has performed much work on such forms as Aster tripolini.29 A very beautiful adaptation one finds in the Cucurbitaceae, Macrozamiamacrocarpa, in the fruit of the oak, of the maple, Compositae, Clematis, Epilobium, pine pollen, etc. Pine pollen has been demonstrated by the author in 1925, 200 km east of the nearest pine tree (Lone Pine) in the Californian desert. The spores of Equisetum, of ferns and mosses, the seeds of tobacco, of orchids are also fit for wind transport. Among flying animals, a great many function as a ‘glider’ and may cover enormous distances. Dr. N. Tinbergen told one about an aphid swarm arriving at Disco, Greenland, from Siberia.30 The author observed 170 miles S.W. from the nearest New Guinea coast, honey birds and butterflies, carried by a strong N. Easterly wind.
Between the free fall:
and the fall in a viscous medium, obeying Stoke’s law velocity v,
for a sphere, radius r, density of falling particle d, density of medium d’, viscosity 𝜇, there exists a transition range. Also, for non-spherical objects a different fall velocity has to be expected. The subject also touches aerodynamics and its full treatment lies outside the scope of this essay. The resistance, exerted by an object against a current
in which r2 represents the cross section of the object and v the velocity of the current, k is a constant and n is dependent on the stream velocity and fluctuates from medium speed to slower laminar movement from 2 to 1.
For flotation we obtain the limit
or the vertical current of air, carrying the organism should measure:
in which c is a constant. Restating Stoke’s law in another form, we may write:
If this resistance equals the moving force we arrive at the region where accelerated motion changes into constant motion. In that case
Solving for v we obtain for the radius
For high velocities the law does not hold.
The equation of Sudry (1912), derived for objects falling in water
a and b are “form factors.” For small velocities the equation becomes identical to Stoke’s law, for high velocities we obtain Newton’s resistance law
4.3.5 Apparatus of van Overeem
As already said Molisch (1917) used glycerol covered slides to study aeroplankton.33 In relation to hay fever Dr. Benjamins, already in 1917, used this method.34 It still is very instructive to expose such slides for a day on a high pole or on a roof to see what organisms appear. The literature on aeroplankton is surveyed by van Overeem. The great drawback of earlier work, including that of Miquel (1883), Meier and Lindberg (1935) and others, was that, apart from bacteria, only dead organisms were studied. In order to obviate this difficulty, while adhering to rigid sterile control, an apparatus was devised mounted under the wing of an airplane. It consisted of a series of hard glass tubes, open on both ends, and filled with glass wool. The tubes were placed in brass boxes and kept inside a larger, covering box (with overlapping lid), by means of strong springs. The entire apparatus was heat sterilised. From the various individual brass cables led to the cockpit where, by means of lamp controls, the position of the tubes could be ascertained.35
The apparatus was calibrated by my colleague J. Bonger in the wind tunnel of the Aerodynamic Institute at the Technical College Delft. It was shown that 10 minutes exposure at a speed of 140 km/hour, 1 cubic metre of air was filtered. Usually, exposure was made at 200-500-1,000 and 1,500 metres, one tube was always kept as control after the run (which was controlled by bacograph records) the apparatus was opened in a sterile chamber under rigorous sterile precautions and the glass wool divided over several culture solutions (here the solutions should be described). Bacteria, fungi, algae and mosses were obtained. Due to the small number of flying hours. However, results of only five m3 are accountable.
4.3.6 Results of van Overeem
The air was sampled by a meteo-plane of the Netherlands Military Air Force (a Havilland, 1916).36 All samples were taken over the airdrome of Soesterberg of algae Stichococcus and Hormidium, besides several diatoms, were obtained. Two species of Musci, [Funaria hygrometrica Sibth] and [Ceratodon purpureus Brid], were also found.37 July 22, 1935 a sample of air taken at 100 metres yielded after 2 months culture a small object which looked like a young fern prothallus. It was taken from the culture solution with a capillary pipette and after two transfers “planted” in a piece of unglazed tile. Here the sporophyte developed and in the early spring of 1936 the plant was large enough to be classified as a Thymian filix-femina DC (we now have several large plants from the original).38 Captain E. Visch, chief of the meteorological service of our Military Air Force made an analysis of the movement of the air masses previous to their arrival above Soesterberg (Fig. 4.10). It appeared that the last possible vertical motion of this air must have occurred over western Norway, and after that this air mass moved “clockwise” over Germany to arrive in Holland, and over the air during three days later. It therefore appears that our fern did travel at least three days.
The control of the experiment was such as to exclude any doubt. The air transport of viable sparks is proved. This also pertains, of course, to such seeds as Orchidiaceae, Nicotianaetc., pioneers and a great many other living objects, insects or spores, cysts and eggs.
4.3.7 Other distribution factors
(Guppy, 1917). The coconut is the classic case of a water borne fruit which retains its viability after long immersion in seawater. A great many other plants have been tested in this respect. It appears that water borne seeds and parts of plants are in a large way responsible for the rehabilitation of sterilised volcanic islands (see however Bakker on Krakatoa).39 Books on plant “biology” mention endless series of adaptations to water dispersal. (This section should be extended literature not available).
(H. Molisch). The common plantain (Plantago media L) has been aptly called ‘the white man’s footprint.’ Not only this plant but also Senecio, Avena fatua, Bellis perennisetc., follow man everywhere he goes. The tracks of the old Amber roads in Europe are said to be marked by a plant Illicetrum verna.40 Many other instances could be cited!
4.3.7.c Other animals
(Myrmecophilous) plants are not only the classical cases mentioned by Schimper,41 such as Lecropia, Acacia farinosa, Hydrophytum and Myrmecodia, but plants, the seeds of which possess glandular tissue which, through its sugar content, attracts the ants and makes man distribute the seeds (Myrmecodias). Buds are transmitted by animals with woolly pelts. Kerner von Marilaun gives good figures.42 Many seeds are in fruits used as food (apple, cherry).
4.3.7.d Obstacles, area
Although so many instances of dispersal are given, still it seems that the majority of higher organisms stick to a rather narrowly prescribed area. It is the hypothesis of Willis that this area expands very slowly and that the larger its extent, the older the species (or genus).43 This “age and area” hypothesis is much debated, but has been, together with the theory of Wegener, a most stimulating influence on biogeography. It is often astonishing how two races of butterflies, for instance, live only a few miles apart on a mountain slope (Toxopeus, New Guinea) without, apparently, any intermingling.44 Only profound investigation will show the reason of these and many other facts connected with distribution, which we cannot mention here.
4.3.8 Inventarisation of area concepts
The area concept has, in the hands of contemporaneous plant geographers like Danser, Lam and van Steenis yielded much valuable information and has led to important generalisations.45 Nevertheless, we cannot push the idea of area to the limit. Professor Diels, the Berlin plant geographer, has published a well known atlas of plant areas.46 As far as higher plants are concerned, these maps are of great use, but Diels, not satisfied with this, has descended downward into the algae, and published area maps of Desmids! It seems to the author of this book that those maps are really not a map of the distribution of algae, but of the distribution of the algologists, as Desmids are lacking nowhere, are easily transported and are so conspicuously similar in the United States and in the United Kingdom that it requires little commentary to see that they are probably of cosmopolitan distribution. It is remarkable that Charles Darwin when talking about distribution (Origin of Species) gives complete precedence to cosmopolitans and then goes to inquire why the non-cosmopolitans are not of wider distribution! Think of migratory birds, a regular ferry service between the tropics and the moderate climes; what number of algae are ferried over from Central Africa to Holland by swallows and storks? The map of Desmids most probably being a map of algologists we may turn to other area maps which are apparently maps of the distribution of sand dunes, or of peat bogs. There are a great number of higher plants and animals bound to a biocoenosis, but always present in that biocoenosis. The omnipresence of life is our first thesis. The sifting action of the milieu the second. The work of van Overeem has established experimentally the most of distribution. About the selective activity of the milieu see Section 5 of this book.
4.3.9 Integration of “everything is everywhere”
The milieu is a veritable resonator. The modern methods of microbiology are a witness to the fact. There is more, however, if one witnesses the digging of a canal in the dunes, a ditch without communication with other open water, one will be amazed about the wealth of organisms, including fishes, which appear in the body of water within a year. If the milieu is aberrant, the results are even more striking. In 1929 near the salt mines in the eastern part of the Netherlands, Boekelo, a salt bath was made. The brine, pumped up from great depth, was first decalcified by means of alkali, so that a solution, poor in lime and magnesia, pH 9.4 resulted. This was inoculated with seawater, but only one diatom, Rhizosolenia developed. The solution had nothing in common with seawater but the 3 % NaCl. After a few months, however, typical salt loving organisms developed, found by the author in Soda Lake, Nevada, 4 years previously. Now Soda Lake has a composition not unlike the artificial brine of the salt bath. A rotifer, BrachionusMülleri, was apparent and the bluegreen alga Aphanothece, further Dunaliella salina and several other flagellates. The next year even the salt fly, Ephydra, appeared!47 The pupae of which formed veritable floating cakes! The nearest locality where to expect this fly is Mulhouse, ±400 miles to the south east! One could increase the number of examples as well, experimental brine tanks at Leiden have shown similar development (Asteromonas, Brachiomonas). The universal distribution of a great number of organisms seems therefore, well established.
4.4 Latent and Active Life
[Baas Becking inserted in the margin a small sketch (Fig. 4.11).]
A hard spherical object, not readily permeated by water such as often a seed, a pollen grain, an egg, a cyst or a spore. Within its secure shell life is latent. Maybe in a dehydrated stage, water sometimes being replaced by oil. Vitality and water content seem to go parallel in the range of the ‘almost dry.’ In such structures, metabolism is at a very low ebb and this indeed is the reason why these states can persist over such long periods. There is hardly any CO2 produced. In life cycles of insects, we find the pupa and while metabolism may be at a very high level here, still the chrysalis is a structure which may permit in semi-latent condition for a long period of time (Shelford, 1929). We know very little about the well protected buds in higher plants, but it is safe to assume that here also we meet with a structure fit for latent life.
4.4.2 Longevity of seeds and spores: historical
“Dormancy” is the term used by many authors to describe this latent stage. Here we meet with periodic phenomena, chiefly in the animal cycle, often, in a rather vague way called hibernation and estivation. In hibernation the vegetative stage of the animal suddenly shows a drop in metabolism, from eurythermic the animal becomes cold blooded – poikilothermic. Accumulation of waste urea in the blood enhances the comatose condition which we meet in Platypus, Insectivora, rodents and bats. The lipase activity increases, the animal uses its reserve fat. On reawakening the temperature may increase almost explosively. Roubard (cited by Shelford) has developed a theory where, in anthomyid Diptera, dormancy is brought about by a period of intense metabolic activity in which an abundancy of urates are formed. These urates are voided into the malpighian tubules during dormancy. The theory could not be substantiated by experiment of other authors. A high CO2 pressure in the atmosphere may cause animals to enter into a dormant period also.
4.4.3 Longevity of seeds and spores: recent
In 1936 the author obtained from his colleague Prof. J.G. Wood at Adelaide sporocarps of the water fern Marsilia drummondi (common fern in inland Australia called Nardoo) collected during the Horne expedition to central Australia, 1881.48 The sporocarps were sent to the Botanical Museum at Leyden but an enterprising gardener of the Leyden Botanical Garden, Mr. J. Lagendijk, planted the sporocarps and raised beautiful ferns from them. They had been dormant for 55 years. Joly (1840) collected eggs of the phyllopod crustacean Artemia in Troarn, 1830. V. Siebold raised nauplii from those eggs in 1875 (?).49Artemia eggs collected by the author in 1929 had lost their generating power entirely in 1939.50 It may be that these eggs, however, were not efficiently dried. Dr. D. Kuenen still raised nauplii from them in 1937.51 At the laboratory of microbiology at Delft, director Prof. A. Kluyver, there is a sample of soil, obtained from L. Pasteur’s experiments on anthrax, 1868 (?). H.G. Derx cultured the anthrax bacterium from this soil ±1920.52
Seeds may remain dormant for over 40 years, as reforestation has shown in areas which were also previously wooded. The forest herbs and grasses reappeared as soon as the young plantation gave sufficient hummus and shade. Certain Dermestidae larvae (museum beetles) (= Anthrenus museorum) may persist for more than four years in almost suspended animation. Mosses are raised from spores out of old herbaria by Becquerel.53 The greatest span being ±80 years. The above cases should be extended to longevity of agricultural seeds (like Becquerel). The stories of the survival of wheat grains in Sarcophagi are obvious frauds. The literature is also compiled by Molisch (1917).
4.4.4 Hydration and activity54
The work of Beyer has shown the ability of the clothes’ moth to use the water derived not from the combustion of food, but of tissue. He fed moth on wool dried at 105 °C in a dry atmosphere and while the animals lost weight rapidly, their water contents remained the same.55 In mammals this water content cannot be lowered more than 10 % without lethal consequences. Desiccation is chiefly a matter of excessive evaporation, and when this may be checked animals may survive in very dry habitats. The amphibians of the desert (horned toad, Gila monster etc.),56 are provided with a very heavy skin (still amphibians have to respire partly through the skin).
It is known that activity in both animals and plants, sets in when previously desiccated tissue (seed, cyst) attains water again. The reaction is again of an “explosive” nature. Although investigations upon this point are scanty, it is known that enzyme activity is highly influenced by electrolyte concentration of the milieu, and it may well be that in desiccated cells some of the water is still in the “free” condition (see Section 3.5.21) but that the solute concentration in this water is too high to allow for enzyme action and, therefore, for metabolism. The book of Shelford (1929) gives a number of disconnected and anecdotical statements that need much amplification. It seems that experimentation upon this most interesting topic is still scanty.
Another factor, which influences activity of life, is the concentration of the foodstuff. There should be plenty. “Plenty” presupposes a concentration which we find in relation to bacteria, in the gut of a host animal, where a high concentration of foodstuff is present. The bacteria may develop quickly here and produce their own metabolic ergones, which are as insects are to plant life when excreted in the soil.
4.4.6 Abnormal temperatures
(See Geobiologie, Baas Becking, 1934). Latent stages are often highly resistant to extreme temperatures. Dickson et al. (1919) kept the spores of Bacillus botulinus for 4 hours in an oil bath at 150 °C. Not only bacteria but also moulds, and even beetles persist at temperatures of liquid hydrogen (-230 °C (?), Rahm, 1924).57 Beijerinck has tried survival of various organisms in hydrogen and helium. Bluegreen algae, which should be considered as primitive, did not survive, as they lost their accessory pigments, phycocyanine and phycoerythine. Certain fishes (Cottoidae) may be frozen solid for a season.58 Frogs may withstand freezing if only the heart keeps beating. Further facts about frost resistance, in relation to bound and free water are given in Section 3.5.21. Hot springs are treated in Section 5.2.4. It seems that there are many forms of protoplasm that do not coagulate under 70-80 °C (bacteria, bluegreen algae, flagellates, amoebae), This section should be materially extended. D2O does not increase the thermo-tolerance of Dunaliella (Baas Becking, 1935).
4.4.7 Summary and conclusions
Susceptibility to high extreme temperatures, as well as latency (dormancy) seem closely related to the water factor. This factor, which we meet everywhere on our path, dictates enzyme action, and enzyme action dictates metabolism. The less the water content of the tissues, the less the approach to boiling point and to freezing point of water will influence the metabolism. If salt loving creatures show a higher dehydration their obvious relation to (or identity with) thermophilic organisms may be accounted for.
Metabolism is the chemical milieu relation with particular references to changes in the internal milieu. Here the living cell either forms compounds with a higher energy contents out of others, of lower potential, like in photosynthesis, or it lowers the energy potential of the substance involved (see Section 4.6). In the first instance it lays up potential energy, in the other case it liberates kinetic energy. Finally, all this kinetic energy will be liberated as heat, as careful energy balances (Algera, 1932; Tamyia, 1932), have shown. Synthesis of the specific protoplasm is one of the most intricate of metabolic processes, a form of metabolism as yet very imperfectly understood (L.W. Henderson, 1913; Chibnall, 1939; Bergmann).59 The basis of all plasmic systems, as well of all energy related metabolism is the molecule of β glucose, synthesised by the green plant and convertible in the vast number of metabolites. The details of its mode of origin from the CO2 molecule are still obscure.
4.5.2 Catabolism and anabolism
Catabolic processes are concomitant with a decrease in energy potential of the substances formed (Fig. 4.12). If we take glucose again as reference substance, 674,000 calories may be liberated in complete oxidation to CO2. Anabolic would be all processes, in which the energy potential is varied. If CO2 is taken as a reference substance (potential of 674,000 calories of useful work (free energy) are required to synthesise 1 mole of glucose out of 6 moles CO2). Plasmic synthesis may exceed this value materially. Still, these protein molecules with very high energy value are few as compared to the number of contributing metabolites. In this way the process of plasmic synthesis becomes understandable energetically.
4.5.3 The role of hydrogen, oxygen, water and CO2
See also Section 5.11.12.
Nearly all metabolic processes of which only C, H and O are concerned (glucose metabolism) may be reduced to form pairs of fundamental reactions (Fig. 4.13), what according to some should be reduced to three pairs, to wit:
Hydrogenation and de-hydrogenation,
Hydration and de-hydration,
Carboxylation and de-carboxylation,
Oxidation and de-oxidation.
The last pair may be much less fundamental. The equilateral triangle depicted shows C, H, and O compounds and their atomic compositions, as will be further used in this essay. The arrows give the direction of the reactions. The “sun” in the centre represents glucose.
Plant and bacterial cells are able to reduce CO2, in some cases completely to methane, mostly “halfway” (see diagrams) to carbohydrate. They are able to reduce nitrate, sometimes to nitrite, sometimes to nitrogen and even to ammonia. They reduce the positive pentavalent nitrogen to negative trivalent nitrogen. They are also able to reduce the hexavalent positive sulphur from sulphate to the bivalent negative sulphur in sulphides and in amino acids. There are indications that the pentavalent positive phosphor atom may be reduced to the trivalent negative atom by certain bacteria (see Section 3.8.6), but confirmatory evidence is still lacking.60
The animal cell is unable to perform any of these reductions, and therefore it is apt to stress this point that plant cells are able to reduce the inorganic, oxidised, milieu, that plant cells are inorgoxidants. This point is of the utmost geobiological importance. For the reduction of nitrates Warburg and Negelein have shown dependence upon photosynthesis.61 This dependence does not exist in bacteria, neither the other inorgreductions. The intrinsic meaning of all this is that plants are able to reduce hydrogen-oxid, water to hydrogen and oxygen.
The photosynthont makes use of sunlight to reduce the carbon dioxide. Nearly all of these organisms possess special organelles, plastids, in which several pigments are present. Only in photosynthetic bacteria and in the bluegreen algae such plastids cannot be demonstrated. The pigment chiefly concerned in photosynthesis is chlorophyll. The enchlorophyll absorbs light maximally at an in the red region of the spectrum (maximum at 6810 Å). The purple bacteria possess an absorption maximum at the near infrared (8900 Å). The mechanism of the process is but imperfectly understood. Most probably, per molecule of CO2, two molecules of water are decomposed on or near the chlorophyll, using four light quanta to perform this feat. The hydrogen is transferred to the CO2, two atoms being incorporated in the molecule, and two others used to form one molecule of water, the over-all reaction being:
HCOH stands for 1/6 of the molecule of glucose, energy requirement of synthesis being 1/6 × 674,000 cal, almost equal twice the heat formation of water, as the hydrogenation of CO2 takes place with but little energy exchange. The photosynthesis of the purple sulphur bacteria takes place according to:
or, in general, the equation should run:
In certain cases, X may be zero and we get a direct CO2 accumulation by means of hydrogen (purple bacteria, algae, sulphate reducers). Chlorophyll has been found in petroleum (Treibs, 1936).62 Native chlorophyll was found in grass from a stable in a roman castellum from Drusus’ days (460 A.D) under anaerobic conditions (Neumann, 1940). It is probable that the CO2 is highly hydrated (orthocarbonic acid) before being decomposed (Baas Becking and Hanson, 1937). Products intermediary between CO2 and β glucose have not been established satisfactorily. It is probable that l-ascorbic acid (or other diënolic compounds) plays an important role in the mechanism of the process.
The efficiency of the photosynthesis may be very high, even up to 70 %. Unfortunately, only a very small fraction of the incident sunlight is utilised. The process of photosynthesis is that which makes the earth inhabitable for their organisms. Glucose is the centre of the biochemistry, the substance from which every biological compound may be derived (see Fig. 4.14). It should be emphasised strongly that, in the modern theory of photosynthesis, the oxygen evolved originates from the decomposition of water and not from the decomposition of the carbon dioxide.
As to the light, a minimum of 4 h γ seems to be needed to reduce one molecule of CO2. For the purple sulphur bacteria, it may be concluded that the reaction:
also takes place, but that this reaction is followed by:
Makamura claims to have obtained experimental evidence for this reaction.63 If this were true, the photolysis of water would be the primary reaction again. If hydrogen is given as such it reacts, in the case of the sulphur bacteria (Roelofsen, 1934). Also, in green algae recent work has shown the efficient reaction of hydrogen (Gaffron).64 The substrate of photosynthesis is the plastid, containing always chlorophyll (see Hubert, 1935).65 It is probable that the fluorescent light emitted by the irradiated chlorophyll protein complex activates the H atoms in the maximally hydrated CO2 molecules. The implication of photosynthesis on the milieu will be dealt with in Sections 5 and 6. In the above diagram H2O and O2 are reacting, forming the orthocarbonic acid C(OH)4, which under the influence of light and by absorption of 4h𝜈 [energy of 4 photons in joules; h = Planck constant v = the photon’s frequency] disintegrates into O2 and hydrated aldehyde, which is soon conversed to β glucose (G in the diagram). Energy requirement per mol β glucose 674,000 cal, requiring 12 mols of H2O to be decomposed 4 per mol H2O 56,000 cal, which checks may well with the heat of decomposition of water!
S. Winogradsky, in 1887, discerned bacteria that were able to persist on purely mineral media if only a chemical energy source were made available. Winogradsky (1922) named these organisms “inorgoxidants”,66 because they derived the energy, necessary for the assimilation of the carbon dioxide from the oxidation of inorganic compounds. In nature, there occur a great many of those oxidations, and every single of them is not left unutilised by a specific bacterium. The aerobic chemosynthesicates, as we name them, are therefore almost predictable. We find those that utilise the energy liberated by the oxidation of:
1. Ferrous iron: the iron bacteria (Leptothrix ochracea. Gallionella, Toxothrix, Siderocapsa):
2. Sulphur and hydrogen sulphide, the sulphur bacteria (Thiotrix, Beggiatoa, Thiobacterium, Thioploca, etc.):
3. Hydrogen, the hydrogen bacteria (Hydrogenomonas, B. statzesi, B. pantotrophus)
4. Carbon monoxide, the carbon monoxide bacteria (B. oligocarbophilum)
while most important for agriculture is the oxidation of:
5. Ammonia by the nitrobacteria (Nitrobacter, Nitrosomonas)
6. Nitrite by the nitrobacteria (Nitrobacter)
There are several other groups, chiefly concerned with sulphur compounds, we shall not endeavour to enumerate them all (see monograph by Bunker, 1936).67 We shall deal with the individual groups more in detail, suffice it here to say that, in contrast to photosynthesis the efficiency is usually very low (5-7 %), only for the hydrogen organisms an efficiency of about 25 % is found. Apart from the aerobic organisms, there exists a number of anaerobic autotrophs. All these reactions have in common the generation of hydrogen, which, in this case, is accepted by oxygen, enabling other hydrogen to reduce CO2. This takes place directly in Hydrogenomonas according to 4H + O2 → 2H2O + 112,000 cal. For the other chemosyntheticates we may write, in the sequence of the number of hydrogen-atoms generated:
Now the free energy efficiency of the above forms, as calculated by Baas Becking and Parks (1927) show that the hydrogen bacteria are the most efficient, followed by the methane oxidation, sulphur and ammonia oxidation, while the iron bacteria have a very low efficiency. This efficiency seems to be proportional to the hydrogen yield. Geochemically one can say that the reactions which occur in nature with development of energy (exothermic reactions will find its counterpart, an organism, which makes use of that energy). The presence of a certain organism may therefore be predicted. The presence, however, of the carbon organism has not been proved and the bacteria that lives on ‘gas-leaks’, in laboratory air, Beijerinck’s Bacillus pantotrophus, that should oxidise CO, is probably not a Bacterium, but an Actinomycete. Most of the autotrophs mentioned here are facultative autotrophs. Even the extreme autotroph Nitrosomonas will live, according to Kingma Boltjes on Heyden-Nährstoff (Kingma Boltjes, 1934).68 As far as the CO2 is concerned all inorgoxidants are inorgreductants. Now there are facultative heterotrophs as well e.g., B. soli69 and Sporovibrio desulfuricans, which forms may persist on hydrogen as an only energy source (D. Stephenson).70 A systematic survey of the process of heterotrophs to reduce CO2 in the presence of hydrogen has, as yet, not been made. Hes has shown, that CO2 is probably indispensable in alcoholic fermentation of glucose! What biochemical consequence one should draw from this fact is, as yet, obscure (Hes, 1937).
G. Harmsen (dissertation) on aerobic cellulose decompose (in press).71
Cell-vibrio. 2. Cytophaga (Myxococus?) 3. Polyangides (Myxobact.) (Sorangium, Archangium). 4. Bacilli (+ endospores) = Vibrio + spore! 5. Actinomyces and Micromonospora. 6. Protoactino[myces] and Mycobacteria = Corynebacterium.
4.8 Dependent Organisms
A.J. Kluyver and his school have shown that the line of demarcation between autotrophs and heterotrophs is anything but sharp. A suitable hydrogen donor suffices in most cases whether organic or inorganic in nature makes little difference. However, we should not go so far as to say that no real difference exists between the two realms. As the whole the autotroph may also feed on organic compounds, but the reverse is usually not the case, only in special instances (experiments of M. Stephenson with sulphate reducers) success has been obtained.72 It seems therefore that most organisms are really dependent. It may be worthwhile to investigate the nature of these dependences. In the primitive concept of the cycle (Liebig) there is only question of “food”. Later the energy transaction when also considered. It may be well to classify the power and the want of the living cell.
The synthesis of glucose.
The breakdown of large molecules, yielding glucose.
The breakdown of glucose and energy release.
The synthesis of the specific protein and of the protoplasm.
Synthesis of substances with special (e.g., morphogenetic) function.
These are few organisms, and all of the these belonging to the Plant Kingdom, that are capable to perform all of these feats. From this it appears that the whole pattern of living nature is held together by exchange of substances that gradually “nothing in the world is single” (Shelley; also treated in Section 1 and Section 7.1).
Thus far, organisms were studied chiefly as entities, separate, specific, independent things. It is well to realise that biology cannot be understood by such limitations. Let us test our own power and limitations.
We cannot synthesise glucose; therefore, we need organic food.
We cannot make use of cellulose; we can use starch.
The breakdown of glucose we perform, but we cannot synthesise ascorbic acid, which we derive out of our food.
Synthesis of proteins we can perform, although we need preformed acid, moreover we need certain amino acids which we cannot synthesise.
We cannot perform the synthesis of a great many substances with specific morphogenetic function or of functional importance. Visual purple needs plant carotene, fertility hormone comes from wheat-germ etc!
The dependent organism after having built its body at the cost of others will leave this body sooner or later to the action of microbes. These microbes will mineralise it more or less completely which means that the carbon compounds will all disappear but there may remain something that will form coal or oil. In this way, from the mineral world the plant will emerge and synthesise glucose. But one shouldn’t forget that the richness of the soil is not only mineral (fertiliser problem). Every single microbe in the cycle may contribute an organic minimum substance which substance, as we know is capable of action in very small quantities, in high dilution. Therefore, if organic matter is mineralised, practically all of its carbon has been organic remnants, the nature of which we only may surmise and which make the soil or the water to a very complete biological entity indeed. Even in our C, P chemicals traces of the compounds may occur (asparagin!) and so influence experimental results! The question of the independent organism has not been solved.
4.9 Life Cycles
Jan Swammerdam in his Biblia Naturae was really one of the first to make us realise the dramatic sequence of larva, pupa and imago in the insect world and of the frog. It appeared that the animal changed its milieu several times. Swammerdam’s attempts to homologise the life cycle of the carnation with that of the frog was not so very lucky!73 It took more than two full centuries before the life cycle of the higher plant was finally fully understood (Strasburger, Nawaschin),74 In relation to the milieu, it seems well to consider the life cycle of living beings, especially those that involve a change in mode of life, where an aerial or terrestrial organism alternate with an aquatic. But there is another alternative, of less obvious nature, but equally fundamental, which should be dealt with first.
4.9.2 Alternating generation
The fertilised egg cell or zygote. Z in the diagram (Fig. 4.15), gives rise to an organism with the double (2 n) number of chromosomes. This diploid being shows cells, when mature, which undergo so called maturation – or reduction division – by which process (R in the diagram) the number of chromosomes is back to n (n generation or haploid generation). Male and female sex cells are both haploid, and again give rise to a zygote. Now in nature diploid and haploid, inevitably following one another, are not equally represented in the life cycle of one organism. There are algae (A in diagram) where the diploid phase is brought back to one cell (Spirogyra). There are also organisms where the haploid phase is brought back to one cell (C) as in higher animals. In various algae, but also in certain ferns, both generations seem to be about in equilibrium. The significance of the reduction division in the preparation for sexual activity, the significance of the sexual act has in this “new deal” of the chromosome map in the zygote.
4.9.3 Concomitant phenomena in zoology
In the higher plant the haploid generation is reduced to few cells, in the higher animal even to one cell of each type, sperm and egg. Amongst the great number of existing cases only mention the life cycle of the honey bee (see Fig. 4.16). The queen is only a diploid worker which, in contrast with other workers became fertile by special food (vitamin E!?) The queen is fertilised only once, on the wedding flight. The sperm she keeps in a pouch and may at will fertilise an egg (in which case a worker larva appears) or lay it unfertilised, in which case a drone larva is hatched. The drone is therefore a haploid, and the generation of its sperm does not take place by means of a reduction division.
(About sex determination and sex chromosome see T.H. Morgan).75
4.9.4 Cytology bacteria
(Paravicini, 1918; Löhnis, 1921; Henrici, 1939). There are the bacteria, and bluegreen algae and certain primitive protozoa which lack a nucleus and (therefore?) seem to lack sexual reproduction. It is claimed that these organisms, at least the bacteria also show a certain life cycle, whether genetically induced or caused by the milieu remains unanswered. In Figure 4.17 a long spirillum (1) may disintegrate into small particles (2, 3), and the particles may give rise again to a complete spirillum (4, 5). For higher fungi this reminds us of the theory of Grierson [?] now quite dead!76 As a great many non-spore forming bacteria seem to persist in the most unlike places, and the vegetative state of these organisms is most susceptible to adverse conditions, indirect evidence of such a “bacterio-zyklogenesis” be presented. Whether it is conclusive remains very doubtful.
4.9.5 Life cycles and ergones (parasites)
The most complicated life cycles we find in parasites. Here we often meet with five or more stages and five or more hosts e.g., fly-copepode-snail-fish-man. It is probable that parasites are highly in need of ergones, and that the whole ‘bouquet’ of ergones may only be supplied by an entire series of hosts. Parasites knit the web of life very close. The relation between cycle and milieu is most apparent here. On the life cycle of fishes, the beautiful example of the eel (Joh. Schmidt) should be given. Our European eel is hatched in the Sargasso Sea, first yields a so called glass-fish. The glass-fish is changed into a katadromic spike fish, which takes 1-2 years to become a monté, that means a fish with a hankering after freshwater. The monté swims into the freshwater. After 4-5 years the Dutch eel, when sexual maturity approaches, yearns for salt water, swims anadromically against the Gulf Stream to the Bahama’s where it finally spawns.77
4.9.6 Antithetic alteration
(Hofmeister, Bower, Campbell).78
[Baas Becking inserted Fig. 4.18.]
In mosses and ferns, the alternating of generations goes hand in hand with the alternating of biological character, land plant and aquatic alternating. This process is illustrated in the figures, it will be seen that in the fern both generations are mutually independent and in equilibrium.79
4.9.7 Life cycle of Ctenocladus circinnatus
(Ruinen, 1933, thesis).80 Although the details of the case escaped me, I remember this piece of beautiful analysis of stages in the life cycle in their dependence on milieu (Fig. 4.19). Alkalinity, temperature and salinity of the water all playing a role to induce various modes of growth or of reproduction to be followed. The alga in question is a cosmopolitan (Italy, Russia, Australia, California) occurring in alkaline, saline desert lakes of not too high a temperature. By the study of life cycle and milieu Ruinen (1933) could predict its terrestrial distribution.
(Minot).81 Here we meet with an irreversible process, there had been much waste in the cycle, thrown aside. Now the thing itself is waste and enters into the cycle of matter. Potentially immortal is the protozoön (Woodruff),82 and the unicellular plant, immortal is the “Keimbahn” of the higher organisms. In death, when there are organs, agony sets in with the disturbance of their correlation, then the organ dies, later the tissue, later the cell. In Paramecium first the longitudinal cilia, then the transversal and finally the oral ceases to beat,83 never in movement the animal first rotates and this only around the pulsatorisation [inserted: On death and dehydration, also cf. recent book of Boeke, 1941.]84 Death is of great importance to Geobiology. Mass death, the explosions mortelles a counterpart of the explosion vitale. It is perhaps rarer than geologists assume (Richter, 1931) on the Hunsrückschiefer,85 euxinic phenomena (see Section 7.6.4).86 About the further analysis of death and the longevity of organisms the special literature should be consulted.
It seems in flat contradiction to our thesis “everything is everywhere” to talk about cosmopolitans. All organisms should be cosmopolitans. However, there are impediments, as we have seen to distribution, and the cosmopolitan is the organism with unlimited power of dispersal. It should also be more or less of a living biont, for if it were choosy, it would be everywhere in latent stage, but not present as a growing organism all over the earth. Cosmopolitans should be really the organisms that would accompany the earth longest through its various adventures. They should stick longest to the terrestrial environment. They embrace representatives of nearly every class, lower and higher. Of course, at least the higher forms are a familiar lot!
4.10.2 Natural and terrestrial milieu
In our days a great many organisms have been distributed by man. They often find what are apparently congenial surroundings. We shall mention them haphazardly. Petricola [pholadiformis], borer worm, from N. America, all over the sea in N. Europe. Also, Dreisena, a mollusc and Eriocheir [sinensis], the Chinese wool crab. Franciscus Padre’s brought Avena fatua [common wild oat] to California, together with a mass of other weeds. Eichornia crassipes, the water hyacinth from N. America is now over all the tropical world.87 From the Leyden Botany Gardens there has been introduced the water fern Azolla [duck weed] from N. America, now over N. Europe. From Mexico Opuntsia, all over the Mediterranean and particularly [O.] stricta in Australia, where it could only be killed by bacteria! 88 Well known is the increased distribution of rat and opossum on and of the jack rabbit and fox in Australia. In the tropics very few plants one meets at the wayside are autochthonous. In the case of Javanese weeds, e.g., kerinjore Eupatorium pallescens from which vegetation also Lantana camara. We could continue to give anecdotical examples but enough is given to illustrate the fact that natural and terrestrial milieu are by no means identical for many higher organisms.
It is safe to assume that bacteria are perfectly cosmopolitan in their distribution. This is rather obvious where spore formers are concerned, but it remains a mystery that forms like the purple Spirillae, of which we know no resting stages, are so perfectly distributed in any material we may employ as infection. I remember the time when we made excursions to the good growth of iron and sulphur bacteria. The knowledge of the milieu has given the means to raise them in the laboratory. In certain instances (Azotobacter) the four new minimum metals (molybdenum) to obtain development. Ignorance of those facts may lead to erroneous statements. Of course, there are common and rarer forms, for instance, the pathogens. But the man culture method works without failure everywhere and so shows the cosmopolitan distribution of bacteria.
4.10.4 Other microbes
Ruinen (1933, 1938a, 1938b) and the author (Baas Becking, 1928b) have demonstrated the universal distribution of salt loving ciliates, flagellates and amoebae. The protozoa fauna of the lakes in N.W. Victoria, South Australia, Madura (Dutch East Indies), Bombay, Egypt, California, Portugal and Italy proved to be very similar. So similar, in fact that most differences should be ascribed to influences of the outer milieu. Also, the freshwater forms are similar the world over. When we compare the algae from the N. American by G.M. Smith (1933), with that of the British flora of F.E. Fritsch (1927), the difference is slight. Marine diatoms are equally cosmopolitan. Elsewhere in the book we mentioned Aulacodiscuskittonii Arnott, a form descended from the Congo River mouth and found by us in N.W. Washington, at the mouth of the Columbia River, and one year later at Corinto, Nicaraqua.89 Dinoflagellates, silicoflagellates also belong to the cosmopolitans. For the Foraminiferae see Cushman (1928), Schenck (1928),90 van der Vlerk.91
4.10.5 Algae and fungi [and higher plants]
4.10.5.a Algae and fungi
H.R. Sinia, at the Botanical Lab at Leyden cultured dune sand in culture solution at a temperature of 30 °C.92 To his surprise he raised several tropical forms, that were apparently present in latent form but could not develop in the infra-optimal temperatures. E. de Wildeman,93 in Algae Flora of Buitenzorg, Java, shows, moreover the general cosmopolitan nature of most of the green freshwater algae (as far as the Phaeophyceae [= brown algae] are concerned, real marine forms, seem to be geographically fixed for some reason or other. At least the forms in Holland, Java, Karachi, Sargasso Sea, Nicaragua, California, Celebes and South Australia are all different. With higher fungi Lütjeharms94 and also Boedijn95 find a great number of cosmopolitans. Many tropical non-fruiting mycelia are common European species (Rand).
4.10.5.b Higher plants
Molisch (1921?) described the agricultural weeds from all over the world. Of course, here man has taken a hand, but there are other plants cosmopolitan, not transported by us.96 In the first place Pteridium aquilinum, the bracken. The author found bracken in California, Washington, Nicaragua, Salvador, Java, Celebes, S. Australia, Victoria, Scotland, England, Holland, Belgium, France, Germany. It hardly can be otherwise or the spores are universally transported by wind. It is one of the most conspicuous of the cosmopolitans. Ruppia maritima and rostellata [= beaked tasselweed], an aquatic, occurring chiefly in brackish water. The author found it Bay of San Francisco, California, York Peninsula, S. Australia, the island of Madura, near Java, near Bombay, British India, near Setubal, Portugal and the island of Terschelling, Holland, dispersal through water (?). Lantana camara [= common Lantana] is a Hawaiian Verbaenaceae plant which has conquered the entire tropics, new and old from Congo to Hindustan and points west. Senecio vulgaris [= groundsel], Bellis perennis [= common daisy], Poa annua [= annual meadow grass], Plantago media [= hoary plantain] belong to the white man’s trail. The book of Molisch, mentioned above, should be consulted.
4.10.6 Higher animals
4.10.7 Summary and conclusions
[Baas Becking left this section blank.]
|Cassia multijuga Reich||158 years|
|Cassia biocapsularis L||115|
|Leucaena leucocephala L||99|
|Dioclon pauciflora Reich||93|
|Astragalus massilliensis Lam||86|
|Cytisus biflorus L’Hér.||84|
|Mimosa glomerate Forssk.||81|
|Cassia multijuga Reich||158 years|
|Cassia biocapsularis L||115|
|Leucaena leucocephala L||99|
|Dioclon pauciflora Reich||93|
|Astragalus massilliensis Lam||86|
|Cytisus biflorus L’Hér.||84|
|Mimosa glomerate Forssk.||81|