SIR,--As I believe that Salmo Salar is quite as desirous of increasing the breed of Salmon as myself, the controversy between us may be reduced to very narrow limits. He believes that Trout eat very few of the Salmon ova, and therefore cannot do much harm. I will just mention a few facts which make me think otherwise. When Ramsbottom was in Galway he caught in one night twenty-five Trout on the spawning ground, which had on the average not less than five hundred ova in each of their stomachs; from one of their throats he squeezed a thousand. As the net would not take a fish of less than two pounds, how many had passed through it? When he was at Knowlmere, in sweeping the river for spawning fish he caught nine Par, two Trouts, and a Sprod on the spawning bed, all of which were gorged with Salmon spawn; when he went into the brooks there he never found a pair of Trout spawning without also finding a number of smaller fish behind, some of which he caught, and in all such cases found them gorged with roe up to the throat; the male Trout would occasionally drive them off, but as soon as he returned to the female they were again close in the rear. In the "Perthshire Courier" of the 22nd December is the following statement: The men employed in taking the breeding fish secured a Whitling on Tuesday about three-quarters of a pound, and as they observed Salmon ova coming out of his mouth he was brought to the office of Mr. Buist for examination; on being opened, upwards of three hundred impregnated Salmon ova were taken from his stomach quite undigested. It may be, therefore, fairly presumed, that this youngster had taken this quantity for his breakfast; if he dined and breakfasted in the same style each day during the breeding season, it is difficult to estimate the expense of his keep. Such is the amount of loss of impregnated roe in one morning from one trifling fish; what must it be throughout the season from the various enemies it has to encounter?