4i6 



S. J. H(Auies 



In a specimen cut longitudinally part way through the body 

 (Fig. 7), regulation was effected by the meeting and fusion of the 

 cut surfaces. The movements of this specimen were of interest. 

 As it swam forward the two sides became crossed. During back- 

 ward swimming on the other hand, they diverged very widely. 

 This is doubtless due to the fact that in the lengthening and short- 

 ening that respectively accompany the forward and backward 

 movements of the organism the marginal regions of the body are 

 more active than the middle. The mechanism of the extension 

 of the sides I have not ascertained. 



THE ROLE OF MOVEMENTS IN REGENERATION 



The foregoing experiments make it probable, as Child has 

 attempted to show in other forms, that the role of the movements 



Fig. 7 Regulation in a specimen cut longitudinally as shown in 7. In 2 is shown the shape assumed 

 when the animal is swimming forward; 5 shows the fcrm during backward swimming. 



of the organism in bringing about the normal form of the body 

 is an important one. There are, in fact, few cases in which the 

 efficacy of the factor of movements seems more manifest. To a 

 considerable extent at least the organism seems to pull itself into 

 shape. It has certain ways of acting which, as observations on 

 the behavior of the parts have shown, are characteristic of the 

 behavior of even quite small parts in much the same way as they 

 are of the whole. A small piece cut from almost any region of the 

 body shows the same rhythm of back and forth movements, the 

 same correlation of extension with forward movement and of con- 

 traction with backward movement, and to a certain extent the 

 same oral and aboral bendings as the entire animal. And when 

 one carefully follows the course of regeneration it seems evident 



