164 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
attended their transfer to water of ordinary temperature. In fact, 
they were kept for twenty-four hours in a temperature as low as 32° F, 
withoutinjury. The expediency of resorting to this method is, however, 
questionable, on account of the extra trouble and expense of manipu- 
lation where the work is carried on upon a large scale. Experience 
has taught that in nearly all fish-cultural operations it is best to con- 
duct them under natural conditions as far as possible. 
The observations made by Dr. C. F. Hodge, during the summer of 
1889, respecting the feeding of young lobsters in confinement, while 
not successful from a practical standpoint, furnished some interesting 
facts regarding the larval habits of this species. The stomachs of speci- 
mens, about one month old, taken at the surface in Woods Holl har- 
bor, contained fragments of copepods and of the larval stages of crabs, 
showings so far as these examinations go, that their normal food at this 
age consists of active crustacean forms having the same pelagic habits 
as themselves. In the aquaria they were supplied with all sorts of 
food, both animal and vegetable, which it was conjectured might be 
suited to their tastes and needs, including surface towings brought in 
from the harbor. They did not appear to touch anything. of a vegeta- 
ble nature or any preparations made from flour. They will eat almost 
any character of animal food if suitably prepared, but while some kinds 
seem to be beneficial to them, others are more or less harmful, the 
yolks of hard-boiled eggs and freshly coagulated milk belonging to the 
former category. When well supplied with nutriment they rapidly 
gorge themselves, and it was found necessary to take much pains in 
dividing the solid particles, which should be neither too fine nor too 
coarse, to insure their proper feeding and prevent their becoming en- 
tangled in the loose tissues. In none of the trials, however, did more 
than a small percentage of the larvee survive for any considerable 
length of time. They appeared to rest mainly upon the bottom of the 
aquarium at night, but rose toward the surface whenever a light was 
brought nearthem. In thedaytime, also, they feed chiefly on the bottom, 
and are apt to spend much of their time there even when not so occupied. 
Dr. Hodge is inclined to believe that the difficulties in the way of 
raising young lobsters in the aquaria do not arise entirely from their 
feeding habits, but are due in part to other causes, not at present un- 
derstood. He experimented upon the effects of light, of temperature, 
of the conditions of the water, ete., but without producing any modifi- 
cations in his results. Larvae confined in floating ears off the wharf, 
moreover, fared no better than those kept in the laboratory. It has 
been suggested that a minute protozoan, which constantly swarmed 
about the living young, and completely infested their dead bodies, may 
to some extent have been instrumental in their destruction, a matter 
that could readily be determined by a sterilization of the water, but it 
is improbable that such a widespread mortality could result from such 
a Cause, 
