PHYS.—I am sorry we did not examine more minutely the weight and size of the fish we caught, and compare the anatomy of the salmon and the sea trout; but we were in too great a hurry to see them on the table, and our philosophy yielded to our hunger. HAL.—We shall have plenty of opportunities for this examination; and we can now walk down to the fishing-house and see probably half a hundred fish of different sizes, that have been taken in the cruives, this evening, and examine them at our leisure. ALL.—Let us go! PHYS.—I never saw so many fish of this kind before; and I conclude that heap of smaller fish is composed of trout. HAL.—Certainly. Let us compare one of the largest trout with a salmon. I have selected two fresh run fish, which, from their curved lower jaws, are, I conclude, both males. The salmon you see is broader, has a tail rather more forked, and the teeth in proportion are rather smaller. The trout, likewise, has larger and more black brown spots on the body; and the head of the trout is a little larger in proportion. The salmon has 14 spines in the pectoral fins, 10 in each of the ventral, 13 in the anal, 21 in the caudal, and 15 in the dorsal. The salmon measures 38½ inches in length and 21 inches in girth, and his weight, as you see, is 22¼lbs. The trout has one spine less in the pectoral, and two less in the anal fin, and measures 30¼ inches in length, and 16 inches in girth, and his weight is 11lbs. We will now open them. The stomach of the salmon, you perceive, contains nothing but a little yellow fluid, and, though the salmon is twice as large, does not exceed much in size that of the trout. The stomach of the trout, unlike that of the salmon, will be found full of food: we will open it. See, there are half digested sand eels which come out of it. PHYS.—But surely the stomachs of salmon must sometimes, when opened, contain food? HAL.—I have opened ten or twelve, and never found any thing in their stomachs but tape-worms, bred there, and some yellow fluid; but, I believe, this is generally owing to their being caught at the time of migration, when they are travelling from the sea upwards, and do not willingly load themselves with food. Their digestion appears to be very quick, and their habits seem to show, that after having taken a bait in the river they do not usually seek another, till the work of digestion is nearly performed: but when they are taken at sea, and in rivers in the winter, food, I am told, is sometimes found in their stomachs. The sea trout is a much more voracious fish, and, like the land trout, is not willingly found with an empty stomach. PHYS.—I presume the sea trout is the fish called by Linnæus, in his Fauna, _Salmo Eriox_? HAL.—I know not: but I should rather think that fish a variety of the common salmon.