Yule marble has been deformed at 300°C, at 5000 atmospheres confining pressure, under conditions otherwise identical with those at room temperature and at 15O°C (Parts I-IV). The important new effects are: apparent development of intergranular flow (recrystallization1) and development of textures closely resembling those of naturally deformed marble. Fabric measurements on the deformed material show trends nearly identical with those observed in specimens deformed at lower temperature (Parts III and IV). The effect of interstitial water is negligible except for lowering of strength similar to that observed at room temperature. Slow rates of deformation seem to favor recrystallization. Granite has been deformed plastically for the first time.