40 GYMNOSPERMS 



Why no embryos are found is still a mystery. They are abundant 

 in the Bennettitales, and structures as delicate as these embryos may 

 have been are well preserved. 



Although it may seem presumptuous to dispute the claims of the 

 two greatest living paleobotanists, Scott* and Seward, nevertheless, 

 a lifetime study of the comparative morphology of living plants, 

 especially Pteridophytes and Gymnosperms, makes me feel confident 

 that the course of evolution has been from homospory, through het- 

 erospory, to the seed. The genetic line must have been homospo- 

 rous Filicales, heterosporous Filicales, Cycadofilicales. 



* I). H. Scott (lied on January 29, 1934. 



