948 | REPORT OF COMMISSIONER OF FISH AND FISHERIES. [6] 
tion and development of the embryo. The works of M. Coste and his 
followers, among others M. Fraiche and M. de la Blanchére, illustrate 
the structure of the young oyster, with its embryo shell and promi- 
nence armed with cillia, which, remaining in a state of perpetual vibra- 
tion, constitute a temporary swimming apparatus. The young oyster, 
by this latter means, sustains itself in the water, until it finds a suitable 
object for its attachment. Then, the temporary swimming organ disap- 
pears, and soon afterward a little shell may be distinguished, about the 
size of a lentil, firmly attached to the side of the collector. 
It has been noticed that mud is not suited to the newly-hatched oys- 
ters, which require a hard and clean surface for their attachment. But 
it was not known when to place such objects in the water, when to offer 
the embryos a suitable surface upon which they could live, for a short 
time at least. é 
Many culturists, observing that the oysters became milky in April and 
May, thought to prepare their collecting apparatus at that time. They 
were entirely deceived, and, in an industrial point of view, unsuccess- 
ful. It was this failure, experienced by Coste himself, which discouraged 
the first attempts. 
M. Chaumel, in an interesting memoir, has given to the commission 
the series of experiences by which he succeeded in meeting the diffi- 
culty. “The situation in 1862~63,” said he, ‘“‘was very trying. M. 
Coste, in discouraging letters, did not disguise from me the fact that he 
was on the eve of seeing his functions as inspector-general suppressed, 
and urged me on to a success which I already began to foresee, and for 
which I tried to make him hope. 
“T was, in fact, convinced that the principle was good, but that he did 
not yet know how to apply it, and it was towards this end that all my 
efforts were now directed. , 
‘““T, as well as the greater number of oyster-culturists, had already 
noticed that the young oyster never attached itself to any but the 
cleaner portions of the collectors, and also that apparatus Which had 
been even fifteen days in the water was already salt. 
‘“‘ Tt, therefore, became absolutely necessary for me to ascertain the 
exact time of spawning, which would, consequently, be the proper time 
for placing the collectors. Upon this success depended. I made many 
attempts to arrive at this desirable result; but what turned out the most 
successful were the most simple. 
“At Pénerf and Auray, I arranged new collectors at every high tide 
after the month of April, and at the same time I opened a few oysters, 
to ascertain the condition of the ovaries. I noticed that the spawn, at 
first white in the ovary, deepened in color as it passed through the 
gills, becoming yellow and violet in turn, as the time of incubation 
approached, and finally assumed a bluish slate-color. When this hue 
appeared, I discovered several young oysters upon the last collectors 
put in place. 
