Nos. 45^-45^-] ^^'^^^^^CA A' SOCIETY OF ZOOLOGISTS. 5 17 



wall of the parent manubrium, attached to this member, after 

 the earliest stages, by a slender connecting stalk. Ten tentacles 

 appear while the larva is still a spherical mass, and as they 

 lengthen assume a direction pointing away from the point of 

 attachment. The mouth and oral tentacles of the actinula are 

 developed after liberation at the pole which was, during the 

 attached period, next to the parent. 



The Development of the Heart and Branchial Blood Vessels of 

 Ceratodns : William E. Kellicott, Columbia University.— No 

 abstract. 



Regeneration in Seyphomedusce : Chas. W. Hargitt, Syracuse 

 University. — Notwithstanding the remarkable development and 

 scope of experimental zoology during the past decade, extending 

 to members of every phylum from Protozoa to Vertebrata, com- 

 paratively little has been done directly upon any of the Medusae, 

 and almost nothing upon Scyphomedusas. The incidental refer- 

 ence of Haeckel to such a tendency among certain of these 

 organisms is hardly more than a hint, with nothing whatsoever 

 as to details. Such is also the case with the later work of Eimer 

 and Romanes on the nervous system of the Medusae, at least as 

 it pertains to problems of regeneration, though painstaking and 

 important in its bearings on problems of locomotion and co-ordi- 

 nated activities. More recently Uexkull has also reviewed some 

 of this work, and while differing in many respects from that of 

 his predecessors as to conclusions, leaves untouched the subject 

 of regeneration. 



The series of experiments of which this abstract furnishes 

 the barest outline was undertaken with a view to ascertain the 

 comparative capacity of Scyphomedusae to reproduce lost jarts, 

 such as bits of the various parts of the body which miglit he 

 lost by the usual exigencies of the struggle of life. The exi)cn- 

 ments comprised some three phases of regenerative energ>' 

 First, the general ability to recover from such injuries as rents 

 of the umbrella, etc.; second, regeneration of such organs as 

 oral appendages ; third, ability to regenerate such specialized 

 organs as the sensory bodies. 



