with some Remarks on the Nature of the Spongiæ Marine. 395 
positively do not exist. I have applied several of the same tests to it as 
Dr. Grant tried on the Sea Sponges*, and with exactly the same results. I 
have gently touched, raised up, and punctured with blunt and sharp instru- 
ments, the delicate membrane, the terminal fibres, the jelly, and the edges of 
the oscules: I have not only touched, but pierced them with a red-hot needle, 
nipped and torn them with a forceps, and have conveyed drops of muriatic 
acid both upon and into them, without the least success. So also M. Du- 
trochett assures us, that he could not perceive any sign of irritability in the 
Lake Sponge, even when under the influence of stimuli. Yet, M. Dujardin 
very recently observing pieces or small parcels of the latter species of Spon- 
gilla, *se mouvoir sur le porte-objet du microscope, en émettant des expan- 
sions arrondies et des prolongemens plus ou moins effilés, comme les Amibest ; 
aussi quelques-unes de ces parcelles se mouvoir d'une autre manière, en agi- 
tant des filamens très longs d'une ténuit? extrême” (p. 7.), announced these 
facts, * des expansions contractiles et des mouvemens de reptation," as suf- 
ficiently demonstrating the animal nature of Sponges. But in this author's 
paper, intitled * Observations sur les Eponges et en particulier sur la Spon- 
gille ou Eponge d'eau douce" (Spongilla lacustris), and just published in 
the ** Annales des Sciences Naturelles," Seconde Série, tom. x. Zoologie, 1838, 
I am unable to discover any single fact which can be brought forward as fully 
proving the animality of either the Freshwater or the Sea Sponges||; on the 
contrary, I can find nothing but what may be equally advanced in favour of 
their vegetability. 
* See Edinb. Phil. Journ., vol. xiii. p. 340. 
See Annales des Sciences Naturelles, tom. xv. pp. 210, 217. 
I This is the Infusorian Proteus. I was not aware that Dr. Ehrenberg had already bestowed the 
new name of Ameba on that genus when I proposed that of Thetis for it. See my short communication 
in the Mag. Nat. Hist. vol. ii. N. S., p. 53. 
$ I have lately read in the Revue Zoologique par la Société Cuvierienne, (Paris, 1838, No. 9, for 
last September, p. 204,) that M. Laurent esteems, as M. Dujardin does, the Spongille to be true ani- 
mals endowed with slow contractile movements. 
In the above-cited paper (p. 5.), M. Dujardin calls the Cliona celata a Spongiaire, which it cer- 
tainly is not, because Dr. Grant has himself not only seen but has also described its extraordinarily 
minute polypes. (See Edinb. New Phil. Journ. for 1826, p. 80; and Johnston’s Brit. Zooph., p. 305.) 
It is therefore a true Zoophyte, and what I may name, agreeably to the modern French nomenclature, 
an Alcyonidiaire, being most allied to the genus Alcyonidium of Dr. Johnston. 
