30 The Unity of the Organism 



terminers," "factors" and the like, constantly used in con- 

 nection with the chromosomes are never used in connection 

 with cytoplasm. Indeed, so well does Conklin present the 

 general argument for the participation of cytoplasm in 

 the development of hereditary structures that it is surpris- 

 ing, not to say disappointing, to find him neglect to present 

 the most specific argument we have to the same effect, name- 

 ly that the genesis of a vast range of such structures can 

 be directly observed to be largely due to cytoplasmic trans- 

 formations. 



One other passage in Conklin's general argument is so 

 significant that we must reproduce it. "Differentiation is 

 indeed the result of the interaction of nucleus and cyto- 

 plasm, and how then can it be said that the nucleus is the 

 only seat of the inheritance material? If held rigidly, this 

 theory involves the assumption that the cytoplasm and all 

 other parts of the cell are the products of the chromosomes, 

 and that therefore the chromosome and not the cell is the 

 ultimate independent unit of structure and function ; an 

 assumption which is contrary to fact. Furthermore, since 

 heredity includes a series of fundamental vital processes 

 such as assimilation, growth, division and differentiation, 

 there is something primitive and naive in the view that this 

 most general process can be localized in one specific part of 

 the cell, something which recalls the long-past doctrine that 

 the life was located in the heart or in the blood, or the 

 ancient attempts to find the seat of the soul in the pineal 

 gland or in the ventricles of the brain." 19 



This passage contains several well-sent shafts not only 

 against chromosomal elementalism, but against the elemen- 

 talist standpoint generally. And I must recur again in con- 

 nection with it, while the facts of egg organization as pre- 

 sented by Conklin are fresh in mind, to the perception, 

 indicated in previous chapters, that the physical-chemistry 

 conception of the cell must be extended to the organism. If 



