312 The Unity of the Organism 



ence of somatogenesis, which was shown at the beginning to 

 be one of the fundamental elements of the problem of hered- 

 ity," and he remarks further: "It is a little difficult to un- 

 derstand why, with such splendid opportunities as the 

 embryological method offers, so little light regarding the 

 hereditary process seems to have come from the embryolo- 

 gist." * 



Importance of Recognizing Heredity as Working by Trans- 

 formation Rather Than by Transmission 



Another weak spot in much thinking about heredity even 

 by some biologists is due to the fiction of "transmitting" 

 characters from parent to offspring. This appears to have 

 come from the original meaning of the terms inheritance 

 and heredity, which have to do with heirship to property. 

 Several recent authors have dwelt on the confusion of ideas 

 that has arisen from this equivocal mode of expression. No 

 one fails to recognize the difference between the transmis- 

 sion of stature and the transmission of a farm by a father 

 to his son. That the difference is partially recognized even 

 in ordinary discourse is seen by the stated beliefs that bio- 

 logical heredity is always associated with resemblance. In- 

 deed, the universality of this association is one of the basal 

 truths in theories of heredity. The real inappropriateness 

 about speaking of organic propagation in terms of economic 

 inheritance is that attention is not called to the fact that the 

 former is accomplished through a long, regular systematic 

 series of transformations to which there is nothing compar- 

 able in the latter. 



The objection here made against the transmission idea is 

 different from that made by most geneticists. Their point 

 is that the germ-plasm conception excludes the possibility 

 of any sort of transmission from parent to offspring. Con- 

 tinuity of germ-plasm is the kernel of their objection. My 

 main point, on the contrary, does not concern the hypotheti- 



