uf the Freshwater Sponges in the Tanks of Bombay. 309 



sewed creeping about, singly or in pairs, with a number of glo- 

 bular bodies within them, varying in diameter from the l-2150th 

 to the l-1075th of an inch ; similar bodies also may be seen here 

 and there, singly or associated together, fixed to the watch-glass 

 l)\" a plastic granulo-gelatinous matter, and bound down by fila- 

 mentous threads (such as I have before mentioned) parting from 

 tlicm in different directions. After some days, from being nearly 

 tiansparent in the first instance, the granular matter with which 

 tliey are filled becomes more defined and evident, and as they 

 enlarge, their circumference presents a cortical investment like 

 T Jiat of the seed-like bodies ; their colour also becomes brownish, 

 and their circumference, from being at first smooth and defined, 

 r )iigh and irregular ; they appear to be motionless in themselves, 

 however much the matter contained within them may assume 

 different shapes, and that peculiarity connected with their size 

 and general appearance is quite sufficient to distinguish them 

 from the granules of the matter in which they are imbedded. 

 In the difierent stages of development I have mentioned, these 

 bodies may be viewed, both within and without the more ma- 

 tured Protean, but, as I have not yet seen them deposited or 

 fixed to the watch-glass by the animal itself, I am unable con- 

 fidently to state that they contain its proper ova; should they 

 prove to do so hereafter, the assumption that the animal itself 

 idtimately passes into the form of a seed-like body may not be 

 worth much. 



The development of the ovum appears to take place in the fol- 

 lowing way: — When first liberated from the spherical cells of the 

 seed-like bodies, it consists of an ovoid or globular sac of green- 

 ish homogeneous matter, surmounted by a red spot, and inclosed 

 within a transparent envelope ; the former then changes in shape, 

 becomes granular, and its gi'anules obtain a certain latitude of 

 motion ; thus transformed, it occupies and projects above the 

 upper part of its transparent envelope, which in its turn enlarges 

 and becomes spherical. Should the ovum in the commencement 

 not have been firmly bound down by the filamentous structiu-e 

 to which I have alluded, the granulo-plastic matter, and the 

 agglomeration of the minute vibrating bodies which accumulate 

 around it, and which appear to be actively engaged in this part 

 of the process, it may become vagrant ; but if otherwise, it has 

 probably become fixed for the whole period of its existence ; un- 

 less, as I have observed in some gemmules when kept in distilled 

 water, that the whole community appear to find it necessary to 

 separate and forsake their spicular structure to go in search of 

 food. 



The form of the young Proteans from the granular matter 

 taken from the seed-like bodies of Nos. 2 and 4 resembles P. 



