OYSTER CULTURE. 199 
M. Davaine in his “Recherches sur la génération des hut- 
tres,” than to see, under the microscope, these little mo- 
lusks travel round the portion of a drop of water, which 
contains them in vast numbers, mutually avoiding one 
another, crossing each other’s track in every direction 
with a wonderful rapidity, never touching and never 
meeting.” 
This curious motive power consists of a great number 
of hair-like filaments, called cilia, which take their rise in 
a dark-colored fleshy mass that emerges from, and over- 
laps the valves of the oyster on the edge opposite to, and 
farthest from the hinge, and operated by powerful mus- 
cles, can be at pleasure drawn entirely within the valves. 
If the young wanderer meets with any hard substance, 
it clings to it, and in a few hours—as it is at this time 
rapidly making its shell—a calcareous deposit fixes it 
there, and, in due course of time, the cilia drop off. But 
even if no such suitable object presents itself, these wan- 
derings must certainly soon come to an en 
The base of the locomotive apparatus gradat nar- 
rows, this organ becomes more and more prominent, un- 
til it is only attached by a single slender membrane to 
the ‘oyster,—which still continues to travel with it,— 
when, at last, it entirely detaches itself from the oyster, 
which at once sinks, incapable of farther motion, while 
the cilia keep on swimming ; but, like a vessel without @ 
helm or pilot, their motion is undirected, they roll over 
and over on themselves, colliding with everything in 
their course, and, though they can hardly be said to die, 
soon cease to move. 
As soon as the cilia are removed, the oyster com- 
mences life in earnest: lips to seize its food, and a stom- 
ach to digest it, are developed; branchiæ, or respiratory — 
