66 THE OCEAN. 
been perceived in them when living, even though 
violence in many modes has been offered to them; 
though beaten, pinched with hot irons, cut or torn, 
or subjected to the action of the strongest acids. 
The substance may be destroyed, but there is no 
contraction, nor the slightest evidence of feeling; 
to all appearance they are as passive as the rock on 
which they grow. One proof of their animality, 
however, is open to any one: we are all familiar 
with a peculiar smell produced when horn, wool, 
feathers, &c., are burned; this smell arises from the 
presence of ammonia, and is peculiar to animal mat- 
ter; on burning a bit of Sponge this animal odour 
is strongly perceptible. On viewing a living Sponge, 
however, in water, with care and attention, it is 
found to exhibit a constant and energetic action, 
which sufficiently shows its vitality. Dr. Grant’s 
account of his discovery of this motion in a native 
species is so interesting, that, though I have quoted 
it in another treatise, I may be forgiven for repeat- 
ing it here. “I puta small branch of the Spongia 
coalita, with some sea-water, into a watch-glass, 
under the microscope: and on reflecting the light 
of a candle through the fluid, I soon perceived that 
there was some intestine motion in the opaque par- 
ticles floating through the water. On moving the 
watch-glass, so as to bring one of the apertures on 
the side of the Sponge fully into view, I beheld, for 
the first time, the splendid spectacle of this living 
fountain vomiting forth from a circular cavity an 
impetuous torrent of liquid matter, and hurling 
along in rapid succession, opaque masses, which it 
