with some Remarks on the Nature of the Spongiz Marine. 371 
were extraneous and parasitical bodies, entirely independent and unconnected 
with the material of the Sponge itself, because they did so extremely resemble 
some of the Infusorian Animalcules. 
These bodies are very minute, though some are less than others, and are 
plainly visible to the naked eye; they are white, of a somewhat globular, or 
rather, more oval shape, the lower or smaller portion being opake, and the 
upper transparent and membranous. Their movements in swimming were no 
less astonishing than elegant ; ascending from the Sponge at the bottom of the 
water to the surface; floating gently on the surface; or traversing the middle 
of the fluid, like a balloon in the air; or suspending themselves nearly in one 
spot ; or whirling round and round, describing larger or smaller circles in the 
water; approaching or avoiding each other; but, when performing their 
quicker progressions, they move along on their sides with their rounder ends 
precedent. Indeed Baker's account of the motions of the Volvox globator *, 
which he calls the Globe animal, is so strikingly descriptive of the movements 
of these germlike bodies, and so similar, that I trust you will pardon me with 
quoting it here: “It moves in all directions, forwards or backwards, up or 
down, either rolling over and over like a bowl, spinning horizontally like a 
top, or gliding along smoothly without turning itself at all. Sometimes its 
motions are slow, at other times very swift; and when it pleases, it can turn 
round (as it were upon an axis) very nimbly without removing out of its 
placet." Roesel has depicted that minute Infusorian in his work on * Insecten,' 
vol. iii. plate 101, at figures 1 to 3 inclusive. Vet the germlike bodies more 
nearly in form resemble the description of Volvox globulus; so much so, that 
* But the spontaneous movements of the Volvor globator are performed by the agency of cilia: 
for, according to Dr. Ehrenberg, its body is furnished with those minute organs. So indeed Baker 
suspected; and he thought that it appeared as if it were set round with short moveable hairs. 
t See “ Employment for the Microscope,” by H. Baker, 2nd edit., Lond. 1764, p. 323. 
i This species I have never met with. But I have just seen many living specimens of V. globator 
under the microscope. I could easily perceive some differences between them and the locomotive germ- 
like bodies of the River Sponge, as well with respect to their colour and structure as their motions. 
These Infusoria are yellower, much more transparent, and more completely globose; within many of 
the larger are distinctly seen several young or round transparent balls, which altogether resemble their 
gravid parents; they swam and moved about with greater power and vigour; and their more active 
and busy movements struck me as if they were under a more decidedly spontaneous control or influ- 
ence. Reesel’s figures above referred to are accurate—J. H., May 16, 1839. 
