ALTERATION OF THE AXIAL GRADIENT. 



227 



the old cell had undergone more or less structural change. Ap- 

 parently all such cases have ceased to grow and are, at least in 

 large measure, quiescent, if not slowly dying. Their suscepti- 

 bility is in general very low. Since this condition unquestion- 

 ably results from the unfavorable environment, the new axes 

 have been inhibited or injured to a much greater degree than the 



old cell because of the originally higher susceptibility associated 

 with their higher metabolic rate. If this is the case the question 

 at once arises, why cell separation has not again occurred. As a 

 matter of fact cell separation was occasionally seen in the new 

 axes, though not very frequently. Its infrequency, even where 



