THE CELLULAR BASIS 185 



but the general polarity, symmetry and pat- 

 tern of the embryo are egg characters which 

 were determined before fertilization. 



It will be observed that the correlation be- 

 tween chromosomes and adult characters is 

 different in kind from that between the cyto- 

 plasm of the egg and adult characters; in 

 the latter case polarity, symmetry and pat- 

 tern are of the same kind in the egg and in the 

 adult, and the correspondence is comparatively 

 close ; in the former there is no correspondence 

 in kind between the chromosomal peculiarities 

 and the peculiarities of the adult. This 

 fact suggests that the chromosomal organiza- 

 tion may be more fundamental than that of 

 the cytoplasm. There are reasons for believ- 

 ing that many substances of the cell are formed 

 by the interaction of nucleus and cytoplasm, 

 and undoubtedly the chromosomes are an im- 

 portant factor in this process. But in no case is 

 the cytoplasm a neglible factor, in no case does 

 it serve merely as food or environment for the 

 chromosomes. The entire cell, nucleus and 

 cytoplasm, is concerned in heredity and 

 differentiation. 



