The size of the Rainbow Trout depends upon its surroundings, the volume and temperature of the water and the amount of food it contains. They vary from the mere fingerlings found in small mountain brooks to those from ten to fourteen pounds, as found in Klamath and other similar lakes. The Rainbow Trout will live in warmer and more sluggish water than the Brook Trout, and for this reason it is being planted in many streams in the east, which are unsuitable for the Brook Trout. It is also being planted in many streams once inhabited by the Brook Trout, but because of the change due to civilization have become unsuitable for them. Rainbow Trout can now be found in many streams of the Allegheny region, in streams in Michigan, in the Ozark region and in many streams of the Western States. The Rainbow Trout is a superior game fish. It is a vigorous biter, and fights bravely for liberty. In no respects is it inferior to the Eastern Brook Trout.

The method of hatching Rainbow Trout is very interesting. At government hatching stations a large number of males and females are kept in ponds for breeding purposes. When ready to spawn the eggs are easily taken from the female by gently pressing on the ventral surface of the body.

After fertilizing them with milt taken in a similar way from the male they are placed in wire trays in wooden troughs through which there is flowing a current of water. In water of 50 degrees F. the eggs will hatch in from forty two to forty-five days. A female weighing one-half to one and one-half pounds will yield from five hundred to eight hundred eggs. One from two to four pounds, two thousand five hundred to three thousand eggs. When the eggs are partly hatched they may be carefully placed in trays and kept free from injury, and packed in ice and sent to any part of the country. In this way they are often sent across the continent, also to Europe, Brazil and Japan. The cool temperature stops the hatching, which will begin again as soon as placed in water of suitable temperature. The fact that so many eggs can be taken from one female and a very large per cent (eighty-five per cent or more) hatched makes it possible to plant, in suitable streams, a large number of young fish each year. If the eggs were deposited in the stream by the fishes themselves the greater number would be eaten by young fishes, crustaceans, insects, etc. Here is a case where man is able to assist mother nature, and to preserve and widely distribute some of our most useful fishes. The Rainbow Trout is receiving much attention and yielding profitable returns. It will always give the angler an opportunity to display his highest skill, and afford a fair recompense for the toil of fishery.