The salmon deposits nearly a thousand eggs for every pound of its live weight, and from the quantity of spawn in some salmon rivers it would seem that nothing which man could do--save pollution--would have any appreciable influence upon the increase of the species. The fecundity of trout is even greater than that of salmon, while a tiny smelt of only two ounces contains upwards of thirty-five thousand eggs, and even these are as nothing compared with the rate of increase of several marine and "coarse" fish. An individual cod has yielded more than six million; a turbot fourteen million; and a twenty-eight pound conger eel fifteen million eggs. The eggs of salmon are nearly as large as the seed of a garden pea, and those of good trout only slightly less. The ova is of a delicate salmon colour and the cell-walls are semi-transparent--so much so that the embryo shows plainly through. Although delicate in appearance they are elastic and capable of sustaining great pressure, and an egg thrown upon a flat surface will rebound like an india-rubber ball. The economy of the extreme prolificness of the sporting fishes of Britain can best be understood when we come to consider the host of enemies which beset both salmon and trout in the very first stages of their existence. Nature is prolific in her waste, and a whole army of nature's poachers have to be satisfied. So true is this that the yearly yield of the largest salmon-producing river in the kingdom is computed at about the produce of _one female fish_ of from fifteen pounds to twenty pounds in weight; the produce of all the rest being lost or wasted. Sometimes a single ill-timed spate will destroy millions of eggs by tearing them from the gravel and laying them bare to a whole host of enemies.[2] These enemies are in the air, on the land, in the water, and nothing short of an enumeration of them can convey any idea of their numbers and wholesale methods of destruction. In addition to the yearling salmon and trout which for ever haunt the skirts of the spawning grounds, there are always a number of mature unfertile fish which for a part of the year live entirely upon the spawn. An instance of this is recorded by a river watcher on the Thames, who states that while procuring trout ova in a stream at High Wycombe, he observed a pair of trout spawning on a shallow ford, and another just below them devouring the ova as fast as it was deposited by the spawner. The keeper netted the thief, and in its stomach was found upwards of two ounces of solid ova, or about three hundred eggs. Eels particularly root up the gravel beds, and the small river lamprey has also been seen busily engaged in the like pursuit. These have a method in going about their depredations that is quite interesting. Small parties of them work together, and by means of their suckers they remove the stones, immediately boring down after the hidden spawn. If a stone be too large