24 Indications of Continued Formative Influence 



This continued action leads us to conclude also that as 

 a further consequence a remote action is exercised by 

 the half embryo already formed upon the parts of the 

 other half which are not in direct contact with the first. 

 This remote action can be transmitted only through all 

 the intermediate cell layers which lie between the surface 

 of contact of the two half embryos and the remote parts 

 in process of postgeneration. 



It would seem necessary then to conclude that the first 

 half embryo exercises upon the far removed parts of the 

 second a remote, mediate and continuous action. 



We shall now provisionally assume that postgenera- 

 tion does not differ in its essential nature from direct gen- 

 eration, and note some consequences which follow for 

 the hypothesis of the central zone of development which 

 during normal ontogenesis would exert an action similar 

 to that which the half of the embryo already formed 

 exerts upon the other half during postgeneration. 



The nuclei obtained as the result of the first divisions 

 of the egg and destined to become somatic, even though 

 derived from those which according to this hypothesis 

 would later form the central zone, would then have to be 

 considered, in relation to the somatizing stimulus exerted 

 by that zone, as quite like the indifferent nuclei of the 

 embryonal half capable of post generation, which receive 

 now this now that stimulus without any preference from 

 the half already developed, and become somatized in 

 consequence now in one way now in another way 

 according as they may chance to be disposed. 



The indifference in respect to somatizing stimuli of 

 these nuclei, which we should at least at the outset 

 suppose like those nuclei from which they are derived, 

 and which later according to this hypothesis give rise 



