114. WORMS, MOSS-POLYPS, SPONGES, ETC. 
SPONGES. 
Among the lowest forms of life that drift to our 
shores are sponges of one kind or another, many 
of them, doubtless, wafted northward on the cur- 
rent of the Gulf Stream, and then distributed by 
local storms. Some of these are of the horny 
character seen in the ordinary sponge of commerce, 
but usually they are of a much looser texture, and 
with a distinct disposition to branch. In the living 
condition of the animal this fibrous mass is envel- 
oped in a soft jelly-like substance, frequently most 
brilliantly colored in tints of yellow, brown, and 
red, which constitutes the active or vitalized mat- 
ter of the organism, the horny fibres themselves 
being merely an accessory in the way of an internal 
support or skeleton. The entire mass is then per- 
meated by innumerable canals, into which the sea- 
water gains access by a multitude of external pores, 
and from which it is expelled into a number of 
larger channels, into which the canalule open, 
and thence into the open sea again. A series of 
perpetual circulations is thus kept up within the 
substance of the animal, the cilia lining the chan- 
nels helping along the water, and with it the 
microscopic food-particles that may be contained 
therein. The excurrent orifices (oscula) are of © 
much larger size than the incurrent pores, and are 
frequently situated, crater-like, on special emi- 
nences. In our ordinary wash-sponges their posi- 
tions are clearly indicated in the larger spaces left 
on the surface between the fibres. 
