Gases from soil and vegetation were analyzed by means of gas chromatography. Less than 1 ppm of each individual component could be reproducibly measured. The vapor obtained by heating soil or vegetation samples in sealed, metal cans contained paraffinic and olefinic hydrocarbons. These hydrocarbons were at least partly formed from plant matter, both living and dead. The spectrogram from soil samples corresponded closely with that obtained from plant rootlets. Soil was tested from areas over oil fields and non-petroliferous areas. These observations make the general application of direct detection of hydrocarbons, or microorganisms utilizing hydrocarbons, from near-surface soil samples of questionable value in prospecting for gas or petroleum.