126 



REGENERA TION 



assume the form of a bell, but the missing parts are not replaced. 1 I 

 have worked on the same form and obtained substantially the same 

 results. If the jelly-fish is cut in two, as indicated by the dotted line 

 in Fig. 39|, A and A', each half closes in and assumes the form 

 shown in B, B. Each new jelly-fish has only the two original radial 

 canals that each half had when separated from the other. A faint 

 line along the region of fusion of the pieces seems to represent a 

 new radial canal, it is not represented in the figures, and each 



iviu. 3_,i. A. Abo.-.il view of Goiiiuttewus verkits. A 1 . Side view of same. Dotted line in each 

 indicates where jelly-fish was cut into halves. B, B. New individual from a half. As seen 

 from above and from the side. C, C 1 . New individuals from a \ piece. As seen from above 

 and from the side. D. New individual from a piece less than J. It contained a part of one 

 of the radial canals. A new proboscis with mouth regenerated in all pieces, but no new 

 canals or tentacles. 



half-proboscis has completed itself. There are not formed any new 

 tentacles, except perhaps one, or a few more, where the cut-edges 

 meet. Thus there is actually very little regeneration, although the 

 typical jelly-fish form is assumed by the half-piece. If a jelly-fish 

 is cut into four pieces, each piece containing one of the radial 

 canals, the . pieces also assume the bell-like form, as shown in 

 C, C' . A new proboscis develops from the proximal end of the 

 old radial canal, and since this end is often carried to one side 



1 Haeckel (1870). first showed, in another medusa, that pieces produce new medusae. 



