CCEIAGE, Dea xa aia 
THE BRYOZOA. 
MARINE plants are frequently found covered with a velvety growth, 
which is evidently the product of a parasite, and not naturally a 
part of the plant. Whether this soft covering be of vegetable or 
animal origin is not readily determined until it is submitted to 
the searching scrutiny of the microscope; all doubt is at once 
removed, and the moss-like growth is found to be a colony of 
animals, whose innumerable cells constitute the “animal moss.” 
This resemblance to moss has given them their name of Aryozoa 
(Bpvov, moss; (@a, animals). They are also frequently described 
in the pages of natural history, under the term Polyzoa (zonXvs, 
many), and they constitute the second group into which the 
extensive class of radiated animals, called Zoophytes, is divided. 
The first group—the Axthozoa (av6os, a flower)—we have already 
considered ; to this belong the corals and those animal associa- 
tions which bear a striking resemblance to flowers. The term 
Zoophyte (Gov, animal; gvtov, a plant) thus comprehends all 
animal productions which approach to a vegetable form, and is 
used indiscriminately with Polypi (moAvs, many; mods, a foot) ; 
a word which must be long ere this familiar to our readers. The 
structure raised by the polypi is termed, as we have seen, a poly- 
pidom; and, on the same principle of nomenclature, “animal 
moss” is a polysoary. 
The microscope enables us to examine each of the members 
of the polyzoary. The animal is found to be ensconced in a cell, 
which is sometimes. fleshy and soft; at other times, horny and 
calcareous. When in its native element, and undisturbed, the 
zoophyte extends out of the orifice of its cell a number of tiny 
arms, which wave about with easy, graceful movements, ever ready 
to enwrap the minute motes of life which form its food. 
This wonderful colony has a common sense of danger; for if 
