REMARKS 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 a, 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 ¢ 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 
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