212 



HEREDITY AND EVOLUTION IN PLANTS 



terrains of the United States, the Black Hills of South 

 Dakota alone yielding a score. The Isle of Portland forms 



FIG. 96. Cycas circinalis. Tip of trunk, showing numerous leaf- 

 stalks, and the large terminal cone. Photo from specimen in Brooklyn 

 Botanic Garden. (Cf. Fig. 95.) 



were called Cycadeoidea by the eelebrated geologist Buck- 

 land. The original nanir of the order was derived from 



