SPO 
Older: animal fixed, torpid, of various 
forms, composed either of reticulate 'fibres, 
or masses of small spines, interwoven toge- 
ther, and clothed with gelatinous flesh, full of 
small mouths on its surface, by which it ab- 
sorbs and rejects water. Between fifty and 
sixty species have been enumerated. S. of- 
ficinalis is irregularly formed, porous, tough, 
lobed, and woolly : It is found in the Archi- 
pelago, Mediterranean, and Indian seas, 
adhering to rocks by a broad base : it is of- 
ten found inclosing small stones, shells, and 
particles of sand : variety of marine animals 
pierce and gnaw it into irregular winding 
cavities, which appear on the outside by 
large holes higher than the rest : its colour 
varies from a pale to a deep yellow : the 
internal part, when cut perpendicular, con- 
sists of small tubes, composed of reticulate 
fibres, and ending on the outside in an infi- 
nite number of small circular holes, w'hich 
are the bibulous mouths of the animal, each 
of which is surrounded by a few erect point- 
ed fibres. Tliis is the common sponge of 
the shops. 
S. ventilabrum, is fan-shaped, regular, 
soft, with reticulate woody veins, covered 
with pores like a honeycomb. This species 
inhabits the Norway and American seas: is 
about six inches high, and five broad : ex- 
actly resembles a small Gorgonia flabellum 
in its shape and ramifications, except that 
the pores ai'e angular, and the substance is 
spongy. 
S. cristata, or cock’s-comb sponge, is flat, 
erect, and soft, growing in the shape of 
cock’s-combs, with rows of little holes along 
the tops, which project a little.. It abounds 
on the rocks to the eastward of Hastings, 
in Sussex, where it may be seen at low- 
water. It is commonly about three inches 
long, and two inches high, and of a pale 
yellowish colour. When put into a glass 
vesselmf sea water, it has been observed to 
suck in and squirt out the water through 
little months along the tops, giving evident 
signs of life. 
S. tomentosa, or nrens, stinging sponge, 
or crumb of bread sponge, is of many forms, 
full of pores, very brittle and soft, and in- 
terwoven with very minute spines. It is 
flill of small protuberances, with a hole in 
each, by which it sucks in and throws out 
the water. It is very common on the 
British coast; and is frequently seen sur- 
SPO 
of gelatinous flesh; but when dry, it be- 
comes whitish, and when broken has the 
appearance of crumbs of bread. If rubbed 
on the hand, it will raise blisters ; and if 
dried in an oven, its power of stinging is 
much increased, especially that variety of it 
which is found on the sea coast of North 
America. 
S. fluviatilis, river sponge, is green, erect, 
brittle, and irregularly disposed in numer- 
ous branches. It abounds in many parts of 
Europe, in the fresh rivers of Russia and 
England, but particularly in the river 
Thames. It scarcely exhibits any symp. 
toms of life ; is of a fishy smell : its pores, 
or mouths, are sometimes filled with green 
gelatinous globules. 
So early as the days of Aristotle sponges 
were supposed to possess animal life ; the 
persons employed in collecting tliem hav- 
ing observed them shrink w'hen torn from 
the rocks, thus exhibiting symptoms of 
sensation. The same opinion prevailed 
in the time of Pliny. But no attention 
was paid to this subject, till Count Mar- 
sigh examined them, and declared them 
vegetables. Dr. Peysonell,in a paper which 
he sent to the Royal Society in the year 
1752, and in a second in 1757, affirmed 
they were not vegetables, but the produc- 
tion of animals; and has accordingly des- 
cribed the animals, and the process which 
they performed' in making the sponges. 
Mr. Ellis, in the year 1762, was at great 
pains to discover these animals. For this 
purpose he dissected the spongia urens, and 
was surprised to find a great number of 
small worms of the genus nereis, or sea sco- 
lopendra, which had pierced their way 
through the soft substance of the sponge in 
quest of a safe retreat. That this was really 
the case, he w’as fully assured of, by in- 
specting a number of specimens of the same 
sort of sponge, just fresh from the sea. He 
put them into a glass filled with sea water ; 
and then, instead of seeing any of the little 
animals which Dr. Peysonell described, he 
observed the papill®, or small holes, with 
which the papillae are surounded, contract 
and dilate themselves. He examined ano- 
ther variety of the same species of sponge, 
and plainly perceived the small tubes in- 
spire and expire the water. He therefore 
concluded, that the sponge is an animal, and 
that the ends, or openings, of the branched 
rounding tucuses. It is found also on the 
shores of North America, Africa, and in the 
East Indies. When newly taken out of the 
sea, it is of a bjight orange colour, and full 
tubes, are the mouths by which it receives 
its nourishment, and discharges its excre- 
ments. 
SPOON-iill. See Pi.atea. 
