94 Mr.H.J. Carter on the Freshwater Sponges of Bombay. 
rior of the cell, securely enclosed in a globular transparent cavity 
resembling a hyaline vesicle, but much larger (Plate IV. fig. 5) ; 
it then attached itself to the upper part of this cavity, assumed a 
globular form, became opake and motionless, and the larger pro- 
tean took on its course. 
Such are a few of the habits evinced by the sponge-cell, deve- 
loped in its natural way and by the process I have mentioned. 
Now, although no doubt may exist in the mind of the reader 
as to the identity of the sponge-cells developed in the natural 
way, and most of those developed from the contents of the seed- 
like body when forcibly expelled ; yet it may be a question with 
him, whether al/ the proteans developed by the latter method 
come from the contents of the seed-hke body, and therefore whe- 
ther the proteans whose habits I have just been describing, which 
slightly differ from those of the sponge-cell, taken from its natu- 
ral structure (only so far as this, however, that I have not seen 
the like evinced by the latter), have not been developed from 
some other source. 
All that I can say in answer to this question is, that although 
the proteans, which have evinced the remarkable habits I have 
described, are larger than the sponge-cell, more active in their 
component parts, more active as a whole, and appear to possess a 
greater share of intelligence; yet their general aspect and com- 
ponent parts being the same, their constant appearance in the 
watch-glass with the other polymorphic cells in the progress of the 
development of the contents of the seed-like body after forcible 
expulsion, when they are nearly as numerous as any other form 
of the protean cells then present, together with the fact, that the 
sponge-cell itse/f frequently contains pieces of confervee within 
duplicatures of its cell-wall, and other foreign matters, just as 
these proteans include within the duplicatures of their cell-walls 
the objects I have mentioned, leaves me no conclusion to come 
to so reasonably, as, that the proteans or polymorphic cells so 
developed are but a higher condition of the sponge-cell met with 
in situ. How they obtain this condition, whether it be from the 
peculiar circumstances under which they are developed, or whe- 
ther it be the development peculiar to a particular class of cells 
of the same animal, are queries for future inquiry to determine. 
Next to the development of the fleshy substance comes that 
of the horny skeleton and its spicula, of which httle more has 
been made known to me by my observations, than has been pub- 
lished by others who have already directed their attention to the 
same subjects. I have not had time to continue my investigation 
beyond the development of the fleshy substance, which is the 
utmost to which the contents of the seed-like body when forcibly 
