536 ALFRED C. H ADD ON. 



Even supposing that the opinion of Salensky is justified, as we 

 shall see immediately, the tissue called nervous is directly 

 derived from the endocyst and that in the young buds of Vesi- 

 cularia spin OS a the granules, at the expense of which the 

 bud is formed, belong to the colonial nervous system, and 

 are only the cells of the endocyst recently detached from 

 the walls, — one may say that the two cases are closely 

 allied." 



But, as in the case of Pedicellina, he begs the question 

 by some such argument as the following : — That, according to 

 Salensky, the new bud. arises from cells proliferated from the 

 endocyst; that the endosarc similarly arises from the endocyst; 

 therefore we may say that in this case the bud arises from the 

 endosarc ! 



It does not appear to me that Joliet^s figures illustrating the 

 proliferation of the endosarc from the "endocyst" are perfectly 

 conclusive. The figure of the bud of Pedicellina, which he 

 refers to above (his pi. xii, fig. 9) really proves nothing. His 

 fig. 1, pi. xii, is possibly more to the point, but then Hatschek 

 (accepting his statements to be true) has disposed of this most 

 thoroughly. The only other figure he gives us is that of the 

 vegetative extremity of a stolon of Bower bank i a imbricata 

 (pi. xii, fig. 2) ; it remains to be proved whether this case falls 

 with Pedicellina, or, if it exists, what is the exact inter- 

 pretation of this proliferation. 



Dr. E. Ehlers (16) describes the phenomena of budding in 

 the form he has more particularly examined, Hypophorella 

 expansa (Ehlers). In the lateral branch from the stolon which 

 is about to form a new animal, and which we may term the 

 bud, he finds externally a cuticle within a nucleated blastema 

 (kernhaltiges Blastem) ; he does not find the two layers 

 which Nitsche describes in Flustra, but has thought, though 

 he cannot prove it, that the outer layer which forms the cuticle 

 may be a Syncytium, though " I have never succeeded in 

 showing nuclei in it," corresporuling to the cylindrical layer 

 found in Flustra. The bud increases greatly in size and early 

 assumes a form much like the adult zooecium. The cuticle 



