KEMARKS ON ^REGENERATION 



339 



I was unacquainted with this observation of Dohrn's, and so 

 made more exhaustive experiments on the subject. I suc- 

 ceeded not only in keeping alive for weeks pieces consisting 

 of several segments, as did Dohrn, but even single segments 

 of the body with only one pair of legs. Animals which I 

 had cut longitudinally did 

 not remain alive, yet I con- 

 sider it possible that further 

 experiments in this direc- 

 tion may be accompanied 

 by better results. 



2. In animals in which 

 the body was divided be- 

 tween the second and third 

 pair of legs (at , Fig. 95) 

 the segments of the body 

 which were cut off were re- 

 generated. This regenera- 

 tion was especially marked 

 in the oral halves of the 

 animals which had to regen- 

 erate the posterior segments 

 (Figs. 96, 97). In the aboral 

 halves of the animals I 

 could discover only a swelling of the anterior end. In some 

 cases a complicated regeneration was recognizable in this 

 swelling. I had to discontinue my observations before the 

 process of regeneration was completed. 



We will now discuss the regeneration of the posterior 

 segments of the body in somewhat greater detail. The 

 regenerated piece ab in Fig. 96 consists of three segments; 

 yet the constriction at c is not as deep as is usual at one of 

 these joints ; in Fig. 97 the regenerated piece ab consists of 

 four segments instead of the three which were expected. The 



FIG. 95 



