CHAPTER IV 



PHYSIOLOGICAL DOMINANCE IN THE PROCESS 

 OF INDIVIDUATION 



According to the theory outhned in chap, ii, the 

 organic individual is fundamentally a dynamic relation 

 of dominance and subordination, associated with and 

 resulting from the establishment of a metabolic gradient 

 or gradients. In the present chapter some of the evi- 

 dence for the existence of dominance in the process of 

 individuation is considered. 



This evidence is obtained primarily from the experi- 

 mental reproductions, because only here is it possible to 

 analyze and control the process of individuation to any 

 considerable degree. The egg is usually a more or less 

 highly specialized individual at the time embryonic 

 development begins, and the earlier stages of its individ- 

 uation commonly occur in such relations to the parent 

 body that they are not readily accessible to experimental 

 investigation. Nevertheless, the evidence indicates 

 very clearly that the process of organic individuation is 

 fundamentally the same in the egg and embryo and in 

 experimental reproduction. 



The evidence presented here concerns primarily the 

 major axis, because the facts are simpler and more com- 

 plete with respect to this axis. Experimental isolation 

 of pieces with reference to the minor axes is usually 

 complicated by the presence of the major gradient, and 

 the order along the major axis is often such that parts 

 necessary for continued life are absent from various 



