588 THE MERMAID’S GLOVE. 
The true living being which constitutes the Sponge is of a soft and almost gelatinous 
texture, to the unaided eye; and with the aid of the microscope is found to consist of an 
aggregation of separate bodies like those of the Amaebee, some of which are furnished with long 
cilia. By the constant action of the cilia a current of water is kept up, causing the liquid to 
enter at the innumerable pores with which the surface is pierced, and to be expelled through the 
larger orifices. A Sponge in full action is a wonderful sight: the cilia drives the water in 
ceaseless torrents, whirling along all kinds of solid particles, arresting those which are useful 
for digestion, and rejecting those which it cannot assimilate. 
The reader will at once see that a creature thus composed will stand in need of some 
solid framework on which the delicate fabric can be supported ; and on examining a series of 
Sponges with the microscope, we find that it is mostly composed of a fibrous and rather horny 
network, strengthened with spicule of a hard mineral substance. The shape of the spicule is 
extremely variable, some being simple translucent bars, some looking much like rough flints ren- 
dered transparent, others star-shaped with several points, while the greater number resemble 
knotted clubs made of differently-colored glass, and having a lovely effect under the microscope. 
In the genus Grantia, which is well known to marine zoologists as having furnished 
valuable information respecting the nutriment and reproduction of the Sponges, no horny 
network can be found, but its place is supplied by the singular form of the spicule, which 
are composed of three long-pointed spines arranged so as to form a star of three rays. 
These rays, on account of their shape, form an entangled mass, and answer the purpose 
of the ordinary horny framework. <A new species, termed Halichondria palmata, inhabits 
the East Indies. 
There are several European species of the genus Grantia. Some of them are hollow, and 
stand out with tolerable boldness from the objects on which they are set, while others are 
always found as whitish incrustations upon stones and other massive substances. Their 
structure is tolerably firm, and, on account of the absence of the horny framework, is not so 
elastic as are the generality of the Sponge tribe ; and the texture is very close, but still porous. 
With a microscope of tolerably high power, magnifying from two to three hundred diameters, 
the layer of spiculee can be readily made out, interlacing with each other in wonderful pro- 
fusion, and so completely intermixed that a single spicula is scarcely ever separable from the 
general mass. 
The shape of the species belonging to this genus is extremely variable, but in ail the 
structure is remarkably simple, the wall being extremely thin, so that the ramifying canals 
are not needed, and the water is merely absorbed through the minute pores of the wall 
and expelled through the large orifice which forms the mouth of the sac. If the spicule of this 
or other Sponges be wanted in a separate state, the animal matter can be removed by heat ; 
but a better, though slower process, is to immerse the specimen in strong nitric acid or liquor 
potassee, according to the flinty or chalky nature of the spicules. When separated they may 
be mounted in two ways, namely, as dry and opaque objects, or in Canada balsam. 
We must now briefly examine a rather important genus of Sponges, which has many 
representatives. It is a very extensive genus, and its members are variously shaped, all, 
however, agreeing in those salient points on which the group has been founded. They are all 
spongy, elastic, not slimy, and with a very porous surface. 
One species is generally called the Mrermatp’s GLove, because it is apt to spread into a 
form that bears a somewhat remote resemblance to a glove with extended fingers. It is cer- 
tainly the largest of the European Sponges, sometimes attaining a height of two feet, and 
stretching out its branches boldly into the sea. The branches are rather flattened, and when 
full-grown are about an inch in width. They do not always remain separated throughout 
their whole extent, but are apt to coalesce in various parts, and sometimes to form rudely- 
shaped arches, 
The color of this Sponge is generally of a pale straw-yellow, and to the touch its exterior 
is decidedly rough, on account of the myriads of spicule which slightly project from the 
surface. These spiculz are needle-like, sometimes slightly curved and sometimes straight. 
Mostly they are pointed at both ends, but as they are fragile and snap asunder with the least 
