OLY NTHOIDEA. 591 
never afterwards can move. The rounded body soon becomes flattened, as it adheres with a 
close grasp, and spreads itself into a nearly circular film. The cilia still exist on the upper 
surface of this film, but the effect of their action is then not to propel the Sponge, but to 
create a current of water which can pass over it. 
As time passes on, the distinctive spiculee become visible, and, after three weeks or a 
month have passed away, the spicule have been gathered into little bundles, which by their 
arrangement tend to preserve the shape of the Sponge and to keep the orifices open. The little 
being now spreads rapidly, by a process which much resembles the subdivision of the Infusoria, 
and the whole mass of the Sponge is evidently composed of a vast number of the Amoeba-like 
bodies which have already been described. Thousands upon thousands of these gemmules are 
passed out into the sea from every Sponge that inhabits its waters; and the only wonder is, 
that, in consequence of such marvellously prolific properties, the Sponges do not swarm to such 
an extent as to fill the whole seas, and poison the entire earth with the odor of their decay. 
THE editor of this edition would state here that though the Sponges were once regarded as 
forming the lowest branch of the animal kingdom, as stated in the original text of this work, 
they now constitute the second in the ascending scale, or next to the lowest, under the title 
Brancu IIl.—Portrerata. As with other branches of the animal kingdom, we refer the 
reader who desires to gain knowledge of the present state of science as applied to this branch 
and that embracing the lowest animals, to the technical tables of classification and nomen- 
clature of the Smithsonian Institution. Not long since, it is well known, they were so little 
understood that no one had quite the courage to say which kingdom they belonged to— 
whether of the animal or vegetable. 
The present state of that section of science which refers to these Jow animals may be 
simply presented as follows: It is now known, as the result of much study and observation 
during the last ten or fifteen years, that the Sponges, in common with all other animals above 
them, are composed of myriads of cells, which perform each their respective offices in the 
animal economy. In some groups perpetuation by division of the body is observed. Yet in 
all these are specialized cells or eggs, for the purposes of reproduction. 
In the first division of the animal kingdom, that embracing the lowest animals, and 
called Brancu I,—Provozoa, it is observed that they differ by having only one simple cell ; 
consequently they do not increase by means of eggs, but by division or segmentation. An 
analagous example is seen when vegetable roots are perpetuated by cuttings. This difference 
suggests to the naturalist two distinct divisions. Those animals having many cells are called 
collectively Mrrazoa, and the single-celled ProvTozoa. 
Sponges are all aquatic ; found in the ocean, and in fresh water to a very limited extent. 
They are all fixed, with very few exceptions, to some object near or on the bottom of the seas. 
The young, during a short period, are supplied with cilia, by which they move through the 
water until they become fixed. Myriads of floating microscopical plants and animals become 
their food by absorption through the pores and open channels so characteristic of these forms. 
The term Poriferata is selected to indicate this branch of animals from this prominent 
feature. The familiar vase form is characteristic of them. Some very beautiful examples are 
familiar. 
The great Neptune’s Cups are interesting forms, being complete vases in shape and con- 
struction, yet in their native element living animal structures. 
Late authorities place Sponges as follows : 
Class I.—Cancispone. Lime Sponges, literally. Yet all do not have the lime spicules 
or skeleton framework of lime formation. 
Order I. An American representative of this order is known through Mr. J. A. Ryder’s 
observations, called Camaraphysema. It is a club-shaped mass, with a tough exterior. 
Order Il.—OtyntHotpEA. This order embraces those forms that have the framework of 
calcareous spicules. Some extremely curious forms of the latter are found, resembling arti- 
ficial objects, as various forms of anchors, spears, ‘‘grains,”’ etc. 
Four sub-orders embrace the comparatively few species of this order. 
