and the Winter-egg of the Bryozoa. 333 



with the branch of canals as a vent ? It is to this that we shall 

 direct our attention more particularly hereafter. 



Meanwhile, when the portion of Spongilla has much increased 

 in size, the older portions begin to bear the reproductive bodies 

 to which I have alluded ; and this brings us at once to the sub- 

 ject of my communication. 



The reproductive bodies of Spongilla are of two kinds, viz. the 

 seed-like bodies, which I shall henceforth term "ova,^' and 

 ciliated gemmules; but it is the former, viz. the "ova,'' with 

 which we are most concerned now, and to the structure and 

 composition of which we are about to direct our attention, in 

 comparison with the "winter-egg'' of the Bryozoa. 



Nothing characterizes the species of the amorphous Spongilla 

 so well as the form and surrounding spicules of the seed-like 

 body or ovum ; and it was during my examination of one of 

 them for this purpose, that I perceived the identity with the 

 "winter-egg'^ of the Bryozoa to which I have alluded. The 

 species to which this ovum belonged, I, in 1848, provisionally 

 termed '^ Spongilla friabilis^ -/' but on a set of specimens (which 

 I had sent home) reaching Mr. Bowerbank, he observed that 

 this was diiFerent from S. friabilis, and referred the question to 

 me, in 1854, with both the branched and amorphous species of 

 England, — kindly proposing, in the event of my being of the 

 same opinion as himself, to do me the honour of calling the 

 Bombay species after me. At the time, however, I was much 

 occupied in official duties, and I could only just examine these 

 species cursorily, but sufficiently for me to come to the same 

 opinion as Mr. Bowerbank ; and having replied to him accord- 

 ingly, I felt quite content to leave the question for ultimate de- 

 cision in his hands, knowing them to be much abler in these 

 matters than my own ; and since then, up to the time of ray 

 writing this, 1 have heard nothing further from him on this 

 particular subject, nor have I recurred to it myself. 



During the last month, however, I have taken up the two 

 English specimens and the Bombay species for more careful 

 comparison, and find not only that all three are different (which 

 no doubt Mr. Bowerbank will notice in his forthcoming work 

 on the " Spongiadse "), but that the seed-hke body of the Bombay 

 species is so identical in structure and composition with the 

 " winter-egg" of a Bryozoon (Lophopus) which abounds in the 

 same freshwater tank with it, that the leading homology between 

 some part of Spongilla and of the lower Invertebrata, for which I 

 have been so long seeking, is thus established. It is also worthy 

 of prefatory remark, that, in the month of May last, I found 



* Annals, vol, iv., 1849. 



