lo George Thoiiias Hargitt 



old perisarc. A new perisarc was secreted about the coenosarc, 

 and a slight annulation was always present in the new perisarc 

 at its union with the old. After the emergence of the coenosarc 

 the red pigment was deposited near the end, and tentacle anlagen 

 were formed, resembling somewhat those in T. crocea (figs. 13a, 

 13Z?). The anlagen were much longer, however, and were usually 

 twisted or twined spirally around the perisarc (fig. 13a), and 

 the distance between the two series of tentacles was much greater. 

 The proximal row was formed first as in T. crocea, but the distal 

 tentacles seemed to form more as those of T. tenella, i. e., as buds. 

 After the tentacles had been formed the hydranth emerged from 

 the new perisarc, and took on the perfect hydranth form. The 

 distal tentacles assumed their full size by further growth. Often 

 gonads began to form before the h)-dranth emerged from 

 the perisarc, or at any rate immediately afterwards (figs. 11-13). 

 Another difiference in the laying down of anlagen is as follows : 

 While in T. crocea the distal anlagen were formed very close to 

 the end of the coenosarc, in T. larynx they developed a consid- 

 erable distance back of the end, thus leaving quite a mass of un- 

 differentiated coenosarc between the distal row of tentacles and 

 the distal end of the coenosarc (figs. 13a, 13^). After the hy- 

 dranth emerged from the perisarc this seemed to be absorbed into 

 the rather short hypostome of the hydranth (figs, ii, 12). 



2. GRAFTING 



Experiments in grafting were tried upon Eiidendriuni ram- 

 osum, Eudcndrium dispar, Pcnnaria tiarella, and Tubularia 

 crocea. The results confirmed those of Hargitt (1899) that 

 union of the same species takes place equally well whether grafted 

 orally or aborally. . However, I was unable to secure a union of 

 Endeiidriuin rauwsnin and E. dispar as he did, though the ex- 

 periments along this particular line were not extensive enough 

 to determine whether this was not due to some unfavorable con- 

 dition. 



The hydroids were operated upon as soon as possible after 

 they were obtained. They were cut into the desired lengths 

 with a pair of sharp scissors, as they left a clean surface and 



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