The talk about the urgent need for the destruction of sparrows reminds me that the word “sparrow” is applied commonly in this country to at least two very different but common birds. No doubt farmers and gardeners know well enough the house-sparrow (Passer domesticus or Fringilla domestica of LinnÆus), which is the one they consider injurious. But some boys and some newly-fledged proprietors of country places may inadvertently confuse the house-sparrow with a very different bird, though only a little smaller and of a general brown colouring, also called “sparrow,” namely, the hedge-sparrow (Accentor modularis).

The hedge-sparrow is a true denizen of the country. It does not live on grain, but on insects and grubs, and is useful on that account to agriculturists. Its eggs are pure blue. A spotted egg of a cuckoo laid amongst them readily catches the eye, so that cuckoos’ eggs are often found in hedge-sparrows’ nests. It seems that it is all a mistake on the part of the cuckoo hen when this occurs. The strain of cuckoos properly attached to hedge-sparrows lay a beautiful blue egg differing only in its somewhat larger size from those of the hedge-sparrow itself, and hence difficult to detect. These blue cuckoo-eggs—proper to cuckoos which make use of the hedge-sparrow as foster-mother—escape detection both by boys and the foster-parents, and successfully hatch out and propagate the race of blue-egged cuckoos with a memory and a sense of smell which bring them back if they are hen-birds to the little hedge-sparrow’s nest when they are grown up and have an egg to dispose of. The spotted grey or brownish eggs are, if not discovered by boys, ejected (there is reason to believe) by the hedge-sparrows themselves. They were deposited by mistake by some pippet-loving or warbler-seeking strain of cuckoo in a hurry, or are throw-backs to a common ancestral colouring of the egg due, perhaps, to the male parent not being of the true blue strain. A very fine series of “clutches” and nests of hedge-sparrow, robin, shrike, reed-warbler, pippet, yellow-hammer, and other birds with the accompanying cuckoo’s egg may be seen in the Natural History Museum, and they show how closely the parasitic egg often resembles that of the foster-parent, though striking failures also occur.

The hedge-sparrow is placed in that group of small birds which includes the robin, the thrushes, and the warblers; it is not a finch. On the other hand, the house-sparrow is a finch, allied to the chaffinch, the goldfinch, and the brambling. It has, like all the finches, a very powerful broad-based beak, and is more than a match for bigger birds than itself. It is really a parasite or “commensal” (messmate) of man, living and flourishing entirely by helping itself to the grain and the young buds of shrubs grown by man, and in towns to the waste fragments of his food and the grain left in horse-dung. Whether it does any good in the early part of the year by eating grubs seems to be doubtful, but the conclusion is justified that it does more harm than good, especially as it drives away other small birds which are exclusively insectivorous. It has gone with European man to all temperate climates. There are Spanish, African, Italian and Indian species, closely related to the common house-sparrow, which I should like to see put out side by side with it and some of its varieties for the public edification in the Natural History Museum. These are the true “sparrows,” and should be compared side by side with the hedge-sparrow, and the differences pointed out.

There is another true sparrow in England, called the “tree-sparrow,” which is not nearly so common as the house-sparrow. They are, however, so closely allied to one another that hybrids have been produced between the two. On the other hand, the hedge-sparrow is a great deal too remote from the finches to interbreed with the house-sparrow or any other of the finch group.

There ought to be a careful report on the probable effects, in every direction, of a great destruction of house-sparrows before any very drastic measures are taken in that direction. The employers of gamekeepers should remember that by destroying owls, hawks, and weasels they may not only enable small injurious birds to flourish in excess, but that they may encourage disease and weakness in the game-birds which they so eagerly desire to multiply, since the natural extermination of weakly birds by birds and animals of prey is put an end to when the latter are abolished. In all such matters more knowledge is needed, and reasonable people will not take irretrievable action until they have taken the trouble to obtain thorough knowledge.

It is a curious fact that though the house-sparrow does not naturally sing, yet hand-reared house-sparrows have been made, by association with bull-finches, to acquire the song of that bird—a truly astonishing instance of hidden or latent capacity.

A lover of trout-fishing has been writing lately upon the question as to whether the trout in much-fished rivers and lakes do or do not exhibit increased “wariness,” or even “intelligent caution” in avoiding the flies so cunningly thrown before or above them by the skilful angler. It is argued that there cannot really be any increased indisposition of trout to take the fly based on experience, because on an estimate of the number of trout in a river like the Test, and of the limited number of anglers, every fisherman would have to hook and lose some thousands of fish every year for the experience to be general among trout that the horrid artificial flies “hide a still more horrid hook.” It is, of course, held that the trout cannot communicate their experiences to one another by any form of conversation (though leadership and imitative habit might have some effect), and it is also not suggested that a trout which had acquired an overpowering aversion to the angler’s fly as a result of being hooked and breaking free, could transmit that aversion to its offspring by the mere fact of reproduction. Hence it is maintained that there is no such increasing “wariness” in English and Scotch trout. It is a curious thing that in discussing this matter the fundamental principle should have been overlooked by which Darwin and Wallace have long ago explained to the satisfaction of naturalists, the aversions and cautious proceedings of all kinds of animals, from the smallest insects up to birds, beasts, and fishes. The principle of natural selection and survival of the fittest accounts for the increased caution of trout in well-fished rivers in the simplest way. Assume (as is perfectly reasonable) that some trout are more shy than others “by nature,” that is to say, are born so, that some are born with a slightly more rapid response to the sight of food than others—as one sees often enough with a lot of the young of any animal—then the increased shyness or pretended “intelligence” of the trout after many years’ fishing follows as a necessity. The rash fish are caught and destroyed, the shy fish remain in the river, and—here is the important point, a well-ascertained fundamental law of heredity—propagate their like. They produce shy fish. Every year this selection goes on till you get a race of fish in the well-fished river which are so shy that they cease to rise at all! This unpleasant result is avoided by the proprietors of trout streams to a certain extent by introducing a race of trout which has not in consequence of over-fishing developed an innate shyness of character (such as the Loch Leven and some others) to mix and breed with the timid over-fished race.

It is in the same way that the human population of country villages, most sad to see, is every year rendered less intelligent than it was a hundred years ago. All the enterprising, intelligent young men and maidens are “fished” away, drawn by baits and hooks to the great towns; only the dull and relatively incapable are left in the village to marry and produce a new generation. The village population necessarily becomes made up of a dull stock—incapable, as appears from official reports, of being educated beyond a very low stage. In some districts 70 per cent. of the children are thus unintelligent, though not unhealthy or imbecile. It is possible that the want of home-training and example in very early childhood is to some extent a cause of the dullness of village children. And so it goes on, generation after generation, as facilities for leaving the village increase and inducements to stay or return decrease. The 30 per cent. of the new generation who have any “wits” leave the village, never to return. And no one re-stocks the village. That must be taken in hand soon.