There are but few salmon rivers in this country. This may be changed by the introduction of the California salmon, which will endure a higher temperature than the trout; but at present the only rivers which can be said to be inhabited by salmon, are those in Maine, Oregon, and California. The former are pretty effectually closed with dams and nets, and in the latter, fish culture is just beginning to be needed. Properly, salmon culture should be the heading of this article, or should take precedence of trout culture, but for these reasons the inferior fish is placed as the title, although we shall take up the management of the salmon first, as its treatment was first discovered, and its manipulation is the most complicated. Under the head of Salmon, may be included the salmon, the trout, the salmon-trout, otherwise called lake trout, the whitefish, the grayling, the fresh-water herring or cisco, and California brook trout, and the California salmon. The scientific names of these are, salmo salar, salmo fontinalis, salmo confinis, salmo amethystus, core-gonus albus, thymallus signifer, and salmo quinnat These are all essentially alike in their mode of culture, the differences being so inconsiderable that they may be disregarded for the present. We shall speak of one for the whole, only occasionally pointing out such individualities as may be necessary.

They spawn in the autumn and winter, with the exception of the California salmon, which is earlier, and spawns in summer and first of autumn, the grayling, a fish of the same race, which has lately been found to exist in our country, and which spawns in March, and the California Brook trout which spawns in March and April.

The salmon comes in from the sea where he has passed the cold weather, as soon as the ice breaks up, and keeps on all summer long running up into the fresh water; which alone, is adapted to the fructification of his eggs. Trout in like manner, pass from the ponds and deep lakes into the cooler streams, where a constant supply of fresh and lively water can be obtained ; whitefish appear from the depths of the great lakes and seeking the shallows along shore, select gravelly and rocky reefs and springy spots to lay their eggs.

Salmon and trout make nests, the females digging out the bottom and fanning away with their fins and tails the mud and finer sand from the gravel which they afterwards use to cover their eggs, and preparing a regular inchoate city of fish fry. When these operations are sufficiently advanced, the male who has been chosen by what Darwin curiously styles "natural selection," that is, a most bitter battle against all comers for the lady in "orange silk or silver lawn," who falls a prize to the strongest, joins his bride. They simultaneously and with one mutual impulse of amatory passion deposit the eggs of the female and milt of the male. Only a certain number of these are extruded at a single impulse, and are then carefully covered over with gravel by the female, while the male divides his time between driving away intruders of his own sex, who would usurp his prerogatives and devouring such stray eggs as may have escaped the notice of his devoted wife, and been carried down stream by the current. One noticeable peculiarity of the spawn of this class of fish is, that the moment it falls from the parent it adheres to whatever it touches. This is a provision of nature to enable the parent to cover it over with gravel before it is washed away, which she does with remarkable skill and care, moving the stones with her ventral fins and tail for that purpose. It remains fast for the space of thirty minutes or so, and then becomes loose and is swept away by the current, a dainty morsel for whatever bird or fish or insect that comes across it. It is also to be observed that the eggs are heavy and sink to the bottom like shot; a marked peculiarity of the spawn of the salmonidae, and distinguishing them from those of other varieties.

Several different deposits of spawn are made and covered up in this way till often quite a mound of fish eggs and gravel is erected. Such mounds built by the famous trout of Rangeley and her sister lakes are large enough to fill a two bushel basket. The operation of emitting the eggs is not all done at one time or on one day, it occupies several days, as will be more fully explained hereafter. As soon as the nest is completed, and the father and mother are exhausted of spawn and milt, they drop back worn out and weakly to the deeper water or the ocean to recuperate. The eggs are left to themselves unprotected, except lor their gravelly covering, and a prey to every passing spoiler.. They were intended to be mainly destroyed, and that intention is effectually carried out.

A similar over supply or wastefulness of nature is visible in all its departments. Seeds of plants and trees are produced by millions to perish by millions, leaving only a few to fructify. Of these few even, but a small percentage lives and reaches maturity. Who has not noticed the innumerable seeds falling from the trees in early autumn, has not seen them driven about by the wind, swept into rows one on the other, carried into the water, crowded into holes and covered up by leaves. Next year out of the countless multitudes, some hundreds start into life, but they are by the way side or on stony ground, or amid weeds, or under the shade of stronger plants. The sun burns some, the shade kills others, the ground starves still more, the ranker growth destroys its share, and so they perish miserably, the exception being if a single one survives. We can partly guess why this superfluity exists, we can connect it in a measure with man's exactions and neccessities.

Enemies of fish life are numerous. First, and most to be dreaded in waters where they exist, are the eels. These are most difficult to exclude from the troughs and ponds. They devour eggs or young with equal voracity. Seven young trout have been taken from an eel six inches long and no thicker than a fine knitting needle; they grow as they eat, hiding most cunningly in the sand or gravel from human eye, and making their way through narrow passages and small holes that a person would not suspect them of being able to enter. One half grown eel will destroy an unlimited number of trout fry or eggs. Ducks are equally destructive, thrusting their long bills down into the nests of spawn, or seizing and swallowing the young ; frogs, mice, rats, fish, many birds, and animals, and the larvae of beetles and devil's darning-needles, and other water flies before they have developed into the perfect insects do their share of damage. Most water creatures love fish spawn as most human creatures admire omelettes.