14 
"laid by the European oyster is given by Eyton, (History of 
the Oyster and Oyster Fisheries, by T. C. Eyton. London : 
1858). He says, p. 24, that there are about 1,800,000, and 
therefore agrees pretty closely with Mobious. 
An unusually large American oyster will yield nearly a 
mubic inch of eggs, and if these were all in absolute contact 
with each other, and there were no portions of the ovaries or 
other organs mixed with them, the cubic inch would contain 
500 3 , or 125,000,000. Dividing this, as before, by tw r o, to 
allow for foreign matter, interspaces and errors of measure- 
ment, we have about 60,000,000 as the possible number of 
-eggs from a single oyster. 
Although each male contains enough fluid to fertilize the 
eggs of several females, there does not seem to be much dif- 
ference in the number of individuals of the two sexes. When 
a dozen oysters are opened and examined, there may be live 
or six ripe females and no males, but in another case a dozen 
oysters may furnish several ripe males but no females, and in 
the long run the sexes seem to be about equally numerous. 
Oystermen believe that the male may be distinguished from 
the female by certain characteristics, such as the presence of 
black pigment in the mantle, but microscopic examination 
shows that these marks have no such meaning, and that there 
are no differences between the sexes except the microscopic 
ones. It is not necessary to use the microscope in every case, 
however, for a little experience will enable a sharp observer 
to recognize a ripe female without the microscope. If a little 
«of the milky fluid from the ovary of a female with ripe or 
nearly ripe eggs, be taken upon the point of a clean, bright 
knife blade, and allowed to flow over it in a thin film, a sharp 
eye can barely detect the eggs as white dots, while the male 
fluid appears perfectly homogeneous under the same circum- 
stances, as do the contents of the ovary of an immature female, 
or one which has finished spawning. When the eggs are 
mixed with a drop of water, they can be diffused through it 
without difficulty, while the male fluid is more adhesive and 
'difficult to mix with the water. By these indications, I was 
