grilse and salmon, under ordinary natural circumstances, do certainly return to their native beds, is one of great practical importance, because it permits the plan of peopling barren rivers by the deposition of impregnated spawn carried from more fruitful waters.  It ought to be borne in mind, however, in relation to this latter point, that these waters must possess, in a considerable measure, the same natural attributes which characterize the voluntary haunts of salmon.  If they do not do so, although the fry bred there will in all probability return thither from the sea as grilse, yet the breeding process will be carried on at first feebly, and then inefficiently, till the species finally becomes extinct.  The same observations, of course, apply to trout.  It has been proposed, we believe by Sir W.F.  Mackenzie of Gairloch, to apply the principle of one set of Mr Shaw’s experiments to the improvement of moorland lochs, or others, in which the breed of trout may be inferior, by carrying the ova of a better and richer flavoured variety from another locality.  Now, in this well-intentioned scheme, we think there is some confusion of cause and effect.  It is the natural difference in food, and other physical features and attributes, between the two kinds of lochs in question, which causes or is intimately connected with the difference in the fleshly condition of their finny inhabitants; and unless we can also change the characters of the surrounding country, and the bed of the watery basin, we shall seek in vain to people “the margins of our moorish floods” with delicate trout, lustrous without any red of hue within, in room of those inky-coated, muddy-tasted tribes, “indigenae an advectae,” which now dwell within our upland pools.

It has been asserted by some that salmon will dwell continuously, and even breed, in fresh water, although debarred all access to the sea.  “Near Kattrineberg,” says Mr Lloyd, in his work on the field-sports of the north of Europe, “there is a valuable fishery for salmon, ten or twelve thousand of these fish being taken annually.  These salmon are bred in a lake, and, in consequence of cataracts, cannot have access to the sea.  They are small in size, and inferior in flavour.  The year 1820 furnished 21,817.”  We confess we cannot credit this account of fresh water (sea-debarred) salmon, but suppose there must be some mistake regarding the species.  Every thing that we know of the habits and history, the growth and migrations, of these fish in Britain, is opposed to its probability.  Mr Young has conclusively ascertained that, at least in Scotland, not only does their growth, after the assumption of the silvery state, take place solely in the sea, but that they actually decrease in weight from the period of their entering the rivers; and Mr Scrope himself, (see pp. 27, 30,) although he quotes the passage without protest, seems of the same opinion.  Besides, with their irrepressible instinctive inclination to descend the