Interpretation of Partial Formations 63 



half of the egg affording such a definite deutoplasmic 

 disposition. 



So it becomes clear that when once the development 

 of the uninjured half of the egg has commenced, the 

 central zone concerned, even though it may be exactly the 

 same as in the complete embryo, would activate only the 

 specific potential energies proper to the corresponding 

 half embryo and would produce only a half formation. 



This half formation no matter how independent the 

 great correlation networks might be, could nevertheless 

 at each instant of its development, render the system of 

 nuclear actions and reactions an incomplete one, without 

 equilibrium, because at the plane of separation there 

 would not be opposed to its own nervous tensions any 

 equivalent system of tensions of the absent half. This 

 incomplete system of nuclear tensions, not of itself in 

 equilibrium, could nevertheless be prevented, even though 

 only transiently, from equilibrating itself normally, by 

 the special distribution of the nutritive yolk and by the 

 presence of the injured half of the egg, still placed op- 

 posite that which is developing. But as soon as the con- 

 tinual increase of energy in the nuclear system overcomes 

 these artificial barriers, equilibrium is once for all upset 

 and postgeneration will appear. 



It is necessary nevertheless to note that some derm- 

 monsters which proceed almost to the completion of their 

 development would seem on the contrary to indicate for 

 this incomplete system of nuclear actions and reactions a 

 practical equilibrium existing from the commencement 

 and persisting through all the stages of development. 

 The typical example of these demimonsters is the famous 

 Hemitherium anterius which Roux so thoroughly 

 describes. It is constituted by the almost fully developed 



