44 
will be destroyed as well. In separate basins, however, 
there is no restriction on the production and the fecundity 
is sO great the accumulation is enormous. Thus while 
one basin is being depopulated others can be repopulated. 
For young fry the smaller crustaceans (Daphnia and 
Cyclops) are required. When probably one and a half 
or two inches long they will be able to take the larger 
ones. Young trout in aquaria will always take these in 
preference to dead food, as it is natural they should. 
This work may be carried even further by making 
wood or cement lined trenches, covered with sashlike 
hot beds, through which the waters of springs may flow, 
for both the fish and food; the inlets and outlets to be 
protected by wire gauze. Such methods involve more 
expense in the beginning but might ee less expensive 
in the end. 
It must be confessed that the eaters only practical 
experience in this direction (except in the handling of, 
trout in aquaria) has been with ornamental fish, the gold 
fish in particular. With these he can say from actual 
experience that as many can be reared in a cemented 
basin covering 200 square feet and costing not over 
fifteen dollars (necessarily), than is usually produced in a 
natural pond of half an acre, and further, that the same 
results can be produced season after season without vari- 
ation, which is not the case in nature. 
And the reason is that in the pond the earlier hatch- 
ings will eat the later ones, while in the artificial basins 
they can be apportioned according to size. The old 
ones will eat the young. The young ones become the 
prey to innumerable forms of pond life from the vora- 
cious hydra to the multitude of water insects and larve, 
crayfish, frogs, snakes, herrons, kingfishers, etc. These 
elements of destruction, everywhere present in nature, 
can be wholly eliminated by the adoption of a proper 
system, while at the same time all the advantages of 
natural conditions may be afforded. 
