Now this description would not at all fit the case of the salmon which live in the North Pacific and ascend the rivers of California, British Columbia, and Alaska, and of Siberia and Japan on the other side of the ocean. These are the salmon which supply the whole country, and many other countries, with their pink flesh, boiled, and sealed in cans, so that it may be sent long distances and kept many months without spoiling. Every spring and summer, at different times according to the locality and the species--there are five kinds of importance, caught for the trade--vast numbers of them enter the mouths of the rivers and begin to make their way up-stream in their effort to reach the shallow head waters of each river, and of every one of its tributaries. It is at this time that they are caught by spearing, netting, and various contrivances; but laws prevent any general obstruction which would altogether stop the advance of the host, so that while tens of thousands are taken great numbers escape and pass on, as it is necessary they should do in order to lay eggs and so keep up the race. This takes place far up at the heads of the streams in the foothills of the mountains; and having deposited the spawn, late in summer, the spent fish begin to drift down stream again. But all this time they have been eating nothing, they are worn with the long struggle against the rapids, often wounded by sharp rocks, and are good for nothing to catch or eat. In fact, so fagged out and weak are they that all of them die before any reach the mouth of the river. It is a strange fact that of all the vast host of salmon which each summer climb the rivers not a single one gets back to the sea. A year later, however, the young hatched from the eggs which were left behind them at the heads of the streams swim down the rivers and enter the ocean. There they remain, probably not very far from land, for two or three years, feeding and growing until they are of full size and strength; and each season a class of them, having reached the right age and condition to spawn, force their way up to the spawning-grounds, to leave their eggs and then die, as did their parents before them. EELS The only other fresh-water fishes which we can notice are the eels, which look more like snakes than fishes, for they have long slender bodies, with a pair of tiny fins just behind the head, a long one running along the back and tail, like a crest, and another, equally long, under the body. And they are clothed with a smooth, slimy skin instead of with scales.