Page:Popular Science Monthly Volume 47.djvu/771

Rh ten inches deep. The bottom is covered with gravel of the size of a pigeon's egg, and the top with boards cleated together in convenient lengths to lift. Here are all the requisites of a nesting place—swift, shallow water, gravel, and shade, with its security from overhead enemies and light. If undisturbed, a {>air of trout would whip a nest in the gravel and lay their eggs and retire after covering them, and the next pair would whip them out again in their efforts to perpetuate their species, and in a state of nature a horde of yearlings would follow the breeders to feast upon the eggs, for of all fish baits the eggs of trout and salmon are among the best. The spawning race is only to entice the trout to spawn there; a net on a frame sliding into grooves at the lower end is slipped in, the covers lifted, and the fish driven into the bag. They are then assorted. Those not ready to spawn to-day or later are thrown back into the pond, the ripe males are put into one tub and the ripe females in another, and to judge of this we note the swollen vent and the softness of the abdomen. This is the first test; the next is the ready flow of eggs.

Here it may be well to say, in nature not more than forty per per cent of the eggs are impregnated, owing to the failure of the milt to reach all the eggs. Of those that are impregnated fully one half are killed by the fungus that grows on the dead infertile eggs, and the remainder are subject to suffocation from freshets, depredations by young trout, eels, ducks, and other animals, as well as the sun, while in our so-called artificial propagation we get such a close contact of milt and eggs that the impregnation amounts to about ninety-five per cent, and there is no loss from sediment, fungus, enemies, nor direct sunlight. There is a loss of perhaps five per cent in deformed fish, such as crooked tails, double heads, twins with one umbilicus, and premature bursting of the shell, but we beat Nature in trout-hatching far more than we do in the breeding of any other animal, and the only comparison that seems fit is' that of cultivating trees and plants, where we produce more than Nature can or does.

Our brook trout usually spawn from November to January on Long Island, in the early part of the day, while the lake trout, improperly called "salmon trout," spawn at night, thus preventing hybridization by means of drifting milt. About 8 a. m. we place a net at the foot of the spawning race and drive the fish that have run up for nesting into it. They are then put into tubs and assorted. The males are put together; the females that appear to be ripe are placed in other tubs, and those which are not near ripe are returned to the pond. A ripe male is known by its slim body and bright color; often his back will be buff, the sides scarlet, and the lower abdomen with a black stripe on each side. The ripe female is soft, and the vent is swollen and protruding.