XII 
REMARKS ON REGENERATION? 
I. ON THE REGENERATION OF THE BODY IN PANTOPODS 
1. So Far as I know, it is generally held that in Arthro- 
pods regeneration is possible only in the appendages, while 
segments of the trunk are not regenerated. According to 
experiments which I made at Woods Hole last year, Panto- 
pods, or at least one form of this group, Phoxichilidium 
maxillara, form an exception to this rule. 
The trunk of Phoxichilidium maxillara (Fig. 95) is about 
lem. long. The animal remains alive for weeks in a dish of 
sea-water. It is, like most of the free-moving inhabitants 
of the surface of the sea, positively heliotropic.* If the 
body of one of these animals is cut in two by a transverse 
incision (at a, Fig. 95), each of the pieces is still capable of 
locomotion. If the pieces are exposed to the light, it is 
found that the oral piece continues to be heliotropic, while 
the aboral piece moves about independently of the light. 
The latter do not show much tendency to progressive 
motion. 
That injured Pantopods can remain alive has already 
been observed by Dohrn. The latter writes: 
I have observed that individuals continued to live for days 
even when all-of the extremities have been cut off. I have even 
cut a female specimen of Barana castelli in two, dissected the 
anterior portion of the body, and kept the posterior portion. carry- 
ing the extremities V to VII, alive for fully four weeks.’ 
1 Archiv fiir Entwickelungsmechanik der Organismen, Vol. II (1895), p. 250. 
2 Part I, p.1. 
8A, Donen, Fauna und Flora des Golfes von Neapel; III, *‘ Pantopoda”’ (Leip- 
zig, 1881), p. 81. ‘ 
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