66 
I had some years ago an opportunity to note, at 
Bucksport, Maine, a phenomenon of like character 
with those recorded at’ Plon: In :the Fall%cr we7em 
built a dam across a brook in Bucksport, to obtain a 
head of water to use in a hatchery. The ground was 
part of an old pasture, and cows waded freely about in 
the brook, and for a time, in the small pond formed by 
the completion of the dam. A portion of the ground 
flowed was a small alder swamp. Late the following 
winter there came down into the hatchery great 
numbers of living entomostraca, mainly Daphnids. 
We practiced at that time the filtering of the water 
through a flannel screen set across the head of each 
trough, and so great was the number of the entomos- 
traca that they often completely clogged up the screens, 
causing the water to overflow. This continued for 
several weeks. The pond was all the winter covered 
with ice, and the mean temperature of the water was as 
follows -in November, 39.1 F.; in Deeember, 35.17 am 
January, 34.5. Whether these entomostraca subsisted 
on their normal food, protozoa, or not, it is evident 
that they found sufficient nourishment even in that very 
cold water, and we are warranted in drawing the 
conclusion that daphnids may not only be bred in water 
cool enough for salmon and trout, but that they may 
probably be brought out at any season of the year by 
proper management. 
The elaboration of methods of managing fish-ponds 
for the production of live food appears to me, therefore, 
to be the most important task to which fishculturists 
can in these days address themselves. It may require 
a great deal of experimentation and study, and perhaps 
much patient waiting, but I cannot doubt that a satis- 
factory system of management will finally be evolved, 
the introduction of which will constitute an advance in 
fishculture as important as the introduction of artificial 
impregnation and incubation. 
