Theories of Chemical Development 277 



special chemical change. This chemical change would 

 later become transmitted to the germ plasm by means 

 of the metabolism. 210 



One can not rightly comprehend here, how a special 

 chemical modification, produced in the germ plasm by 

 a change of form in the adult organism, can later give 

 rise to such a development by that germ plasm as to 

 reproduce the same change of form at the proper time 

 in the new organism. If the chemical variation cor- 

 responding to a definite change of form were provoked 

 by the germ plasm in the new organism only at the 

 time when this latter reached the same age and conse- 

 quently a state of being which would be the same in its 

 entirety as that of the parent organism when this given 

 variation of form supervened in it, and were confined 

 to the same limited zone in which this chemical variation 

 \vas produced in that parent organism, then the concep- 

 tion of an actual reversibility of the phenomena would 

 not be in itself at all impossible, that is it would not be 

 impossible that the same chemical phenomenon might 

 provoke in the new organism the same variation of form 

 by which it had itself been produced in the parent organ- 

 ism. But in our case on the contrary this chemical varia- 

 tion, no matter whether it transforms the whole chemical 

 composition of the germ plasm or only a part, will com- 

 mence to act upon the new organism immediately, at the 

 very commencement of its development, and will modify 

 therefore not merely a limited part of the cells of the 

 organism, but all the cells without exception. How then 

 could this same chemical change, which operates immedi- 

 ately at the commencement of development and conse- 



210 Roux: Ibid. P. 61. 



