TWELFTH ANNUAL MEETING. 53 
water per day, through a small tumbler which I used as my 
breeding-jar. I also introduced water several times a day by 
means of a small sponge. : 
I found that with this arrangement of the vessel I had no dif- 
ficulty in keeping my young oysters alive, and so far as I could 
tell I lost none in the outflow. 
Practically then, the difficulty of maintaining acirculation of the 
water had been overcome, and I maintained an equable tempera. 
ture by placing all my vessels, that is, both supply tank and 
breeding vessel, in a constant stream of water flowing from the 
hydrant; the temperature of the water in the vessels thus chang- 
ing only with the change of the surrounding stream, which was, 
during the course of the experiments, from 74 to 80 degrees. On 
the 25th of July, with a temperature of the water at about 74 
degrees, I placed my frst hatching of young oysters in the ap- 
paratus. F 
My method of impregnating the eggs was as follows: Upon 
opening the oysters, | took a small portion of the generative 
products and examined to see whether the specimen was a male 
or female, and if ripe. Having thus selected a good specimen 
of either sex, I slit the ovaries and spermaries lengthwise with 
many gashes, and then pressed out the products, and gathering 
with a knife, placed them together ina small watch glass and 
mixed them with a little water. Afterward they were trans- 
ferred to a larger vessel containing more water, when they were 
allowed to remain quiet for a considerable time. The surplus 
of milted water was then siphoned off and thrown away, and the 
vessel again filled with fresh water. During the time the water 
in the vessel is quiet, most of the ova settle to the bottom, and 
remain there as a thin layer, which with care will remain undis- 
turbed, while the light ova and the unused spermatozoa are 
drawn off from above. The ova can be washed several times 
if thought necessary, in order to thoroughly cleanse them from 
any particles of organic matter and spermatozoa which may be 
at the bottom, and which by decaying might tend to affect the 
water unfavorably. By the method which I adopted of slitting 
the ovaries and spermaries, and then pressing out the contents, 
I obviated the necessity of cutting the parts to pieces, and after- 
