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[9] OYSTER AND MUSSEL INDUSTRIES. 833 
‘Independently of these natural banks which we would be able to sup- 
port and cultivate, I believe that the raising of oysters, in ponds and arti- 
ficial reservoirs, would become easy by means of artificial fecundation. 
Experiments and researches are here necessary, however, to indicate the 
best processes to pursue; I will simply recall the fact here, and prove 
by the document, that oysters do not appear to dread a certain quantity 
of fresh water. Thus we find these mollusks in considerable quantities 
in Reance, for instance, at such a distance up that, at dead low tide, 
they are bathed by nearly pure, fresh water.” * 
Such are the opinions advanced by M. Quatrefages. 
The most careful researches undertaken upon the reproduction of 
oysters indicate that in all individuals, without exception, the sperma- 
tozoa and eggs are met with in the same organ, and develop there 
together. The cells in which the former are developed are the first to 
arrive at maturity, and the elements destined to effect fecundation break 
from their inclosures when the eggs, which they are to fertilize, begin 
to appear. These mollusks are, therefore, hermaphrodites, since they 
unite in one and the same organ the attributes of both the male and the 
female sexes; this is henceforth an incontestable fact. 
‘If oysters are hermaphroditic, fecundation must take place within the 
body of the animal, that is to say, either in the ovary, which is the 
more probable way, or in the canals [oviducts] which conduct the eggs 
from the ovary into the folds of the mantle, where they are to develop. 
Experience proves, in fact, that it is thus accomplished. When the 
eggs have arrived at the place of incubation, they present all the indica- 
tions of development which imply a previous fecundation. Impregna- 
tion is then an internal phenomenon accomplished before the spawning, 
I might say even before the eggs are detached from the ovary. 
To prove it, it is sufficient to remember that in the oyster the testicle 
and the ovary are one and the same organ; that in this organ the fe- 
cundating elements arrive at maturity and disappear long before the 
ovules break from the ovarian capsules which inclose them. But, if these 
fertilizing molecules disappear before the extrusion of the eggs, their 
action upon the latter must have been anterior to that extrusion; it is 
therefore while the eggs are still in the tissue of the ovary that impreg- 
nation is accomplished. They remain buried in the tissue of that organ 
a long time after this influence is exercised, and grow there considerably, 
only disengaging themselves when they have attained a sufficient size to 
break the walls of the capsules, which they distend. 
Ovarian fecundation so long before the time of the extrusion of the fer- 
tilized eggs is a fact that ought not to surprise us. We find striking ex- 
amples of it among birdsin general, and among the gallinaceous species 
in particular. All physiologists know at the present day that even one 
copulation fecundates 5, 6, or 7 eggs at a time in the ovary of a hen; that 
among the eggs poeedioed at the same time there are some which have 
* Comptes-rendus de Vv Académie des Sciences, Reance du 26 février 1849. 
S. Mis. 2? 53 
