Adaptive Convergence in the Sand Reptiles of the Sahara and of California: A Study in Structure and Behavior

r HERE exist in literature many short remarks concerning the desert adaptations of reptiles, but an extensive comparative study, linking up structure and habits, remains to be made. Continuing work begun on the Sahara in 1926 and 1928, the writer is at present carrying on an investigation of this nature. The similarities found between Saharan and American forms are amazing. From the first it is necessary to clearly differentiate between the adaptations of animals to desert conditions and their adaptations to the sand. The former enable the animal to exist under the severe climatic