with some Remarks on the Nature of the Spongie Marine. 377 
And a portion of it is translated in an article “On the Metamorphoses of the 
Reproductive Bodies of some Algæ, said to possess successively an animal 
and a vegetable Existence,” in the Mag. of Nat. Hist. vol. i. no. 4. for Novem- 
ber 1828, p. 307, and is illustrated by a wood-cut. Here the locomotive glo- 
bules, or more correctly the sporules or germs of the Ectosperma clavata, are 
described as being * oval, dark at one extremity, and almost transparent at 
the other;" which characters exactly resemble those of the sporules of the 
Spongilla. Also the account of their movements and mode of swimming is 
very nearly the same, and is thus translated in p.307 : ** The minute globules 
(were) unequal both in colour and size. Many of them swam freely here and 
there, moving at their option, in one way or another, retiring and approaching 
one another, gliding round globules that were motionless, stopping, and again 
setting themselves in motion exactly like animated beings.” I have therefore 
no hesitation in asserting that the movements of both are in all probability 
effected by the same means. 
But it unfortunately does not appear from Unger's figures in tab. 40, that 
any powerful microscope had been used to magnify the locomotive sporules in 
question, in order to prove whether or not they possessed cilia, or any other 
like organs, by which their motions might be partly or altogether performed. 
Nevertheless I have taken much trouble in endeavouring to ascertain by what 
means the sporules of the River Sponge swim and move about. 
Under the highest power of Jones’s improved compound microscope, with 
which my observations on these sporules, whilst in their fresh and locomotive 
state, were made, I could only perceive certain rapid streams or currents 
taking place on their sides, which induced me to think they were currents or 
vibrations in the water caused by little tufts of cilia, with which the membra- 
nous coverings of the sporules seemed to be furnished, and by which their 
movements, as I fancied, were effected. But having selected many of these 
sporules when in full possession, and at the time they were actually making 
use, of their moving power, I preserved them in a phial of spirits*: some of 
these I have lately (November 26th) re-examined under a more modern and 
perfect instrument, one of Powell’s compound microscopes, and belonging to 
* This phial, containing many of these locomotive sporules immersed in spirits, I beg to present to 
the Society. 
3D2 
