50 FISH—CULTURAL ‘ASSOCIATION. 
were using oysters all this time from shoal water, and it has 
since been pretty well established that oysters in shoal water 
shed their generative products earlier, on account of the gener- 
ally higher temperature of shore waters, than those found along 
the deeper portions of the coasts. 
This is not true in all cases, but probably is true in a large 
majority of instances. Accordingly, we were using oysters 
which had shed their ripe products, and the only practical re- 
sults that I obtained for the first season’s work were to ascertain 
beyond a doubt that the American oyster is bi-sexual, and that 
as a rule they do not carry the young in the gill-chamber upon 
the “beard,” as appears to be the case with the European oyster, 
for out of hundreds examined I only found two with young 
upon the gills and mantles, and even in these instances it may 
not have been the normal position of the embryos. 
The next season, Dr. Brooks located himself at Crisfield, Md., 
early in May, and getting oysters which had not spawned, was 
immediately successful in impregnating the ova, and in keeping 
the young alive for a few days, but in no case did he succeed 
in keeping them longer than a week. He found it impossible, 
with any means at his command, to arrange vessels which would 
retain the embryos, on account of their minuteness, and at the — 
same time permit of a current of water to pass through the ves- 
sels, and thus give food to the growing animals. Others have 
repeated the experiments, but no progress beyond that already 
noticed above had been made when I began my experiments last 
summer. I had been present during a portion of the time Dr. 
Brooks was carrying on his investigations at Crisfield, and noted 
the difficulties with which he had to contend, and it was not 
until later in the season that I thought of a method of arranging 
apparatus which seemed feasible for the end in view. 
I did not, however, have an opportunity to test this new 
arrangement until last summer, when being in New York, Mr. 
Blackford, who is so well known among you for his enthusiasm 
in scientific fish work, kindly placed at my disposal, not only a 
room at the Fulton Market for the purpose of continuing my 
experiments, but with great liberality arranged to supply me 
with such specimens of oysters and such amount of sea-water, 
