376 



WILLIAM H. COLE 



absence of light results in a higher rate of growth. It is not sur- 

 prising, then, to find that the same thing is true of animal tissue. 

 Amorphic regeneration is typical of DN grafts. Only three of 

 them showed tail-like regeneration in addition to the amorphic 

 type. In the light series twenty-four out of fifty-five showed the 

 amorphic and nineteen produced miniature tail tips. It seems 

 that the absence of light hastens the adjustment period, allowing 



TABLE 2 

 The DN series 



Totali 



16 



14 tail 

 2 back 



1 1 



14 



proliferation to get an earlier start, and also increases the rate of 

 proliferation (fig. 14). These two conditions tend to prevent 

 adjustment in those grafts which are slow to show it, and to bring 

 adjustment to a close, in those grafts which have begun to be 

 absorbed, earlier than if they were in the light. With these ex- 

 ceptions, the histories of the LN and DN series were similar. 



