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LETTER V.

SUPPOSE that in the course of our ramble we should observe, under the impending edge of some mossy bank, or on some old and ivied trunk overhanging the stream, the ingeniously formed nest of the common wren. For so small a bird this nest is of very large size, and is of the form of a hollow ball, with an entrance in its side. I hope you already anticipate the questions I am about to put, and that you are making rapid progress in observing nature in the way I wish. When you meet with a natural object in any respect remarkable, or differing from the usual mode in which analogous objects appear, ask yourself why it is so, and find out the reason if you can. Why is the wren's nest of large size and globular form? Why is it not made like that of the hedge-sparrow, or the robin? And does it not seem like a kind of injustice, that so small a bird as this should have to undergo the labour of forming so large a house, when so many other birds, greatly its superior

in size and strength, have no such duty to perform?

In answer to these questions, I would have you to ascertain, in the first place, whether there is any thing that should strictly be called labour in the process. Is it an uneasy, a troublesome, an unwelcome business to the bird? Is the latter under the tyranny of an unjust taskmaster, who will oblige her to go through a laborious, painful, and irksome work, whether she will or not? You may rest satisfied that such is not the case. Does a mother think it a trouble to nurse the child of her affections? When you yourself have spent whole hours in cold and tempest to erect a man of snow, did you think it a labour? You know, on the contrary, that it was the pleasure, and that alone, attendant upon the work, that could have induced you to do it. The bird also has a pleasure in her work; with this difference, indeed,your man of snow melted and disappeared under the first sunshine or mild weather, and without any good result having been produced by the labour; but the operations of nature are never without a final object, and that of the wren's workmanship is one of the most important, namely, the continuation of the species. That birds, in fabricating their nests, in hatching their

eggs, and in bringing up their young, experience the highest pleasure and gratification, is, indeed, so obvious, that little argument would be necessary to prove the truth of the remark.

You are aware that the whole of this important process is the result of instinct, and that the bird, however great may be the pleasure attendant on it, cannot know that heat is necessary to evolve her family from the eggs, nor even that she is to have a family at all; and indeed, notwithstanding our knowledge of chemistry, we are ourselves, in some points of the process, nearly as much in the dark. We know (which the bird does not) that heat is necessary to incubation; but why it should be so, why an egg should not hatch at a low as well as a high temperature, no man can tell: like innumerable other things, we know the effect resulting from the cause, but why it should do so we can tell no more than a child.

Without a knowledge, however, springing from some source, both of the cause and the effect, the bird might lay her eggs in vain; and besides, that knowledge must be of the most profound cast, that it may meet the varieties and difficulties of different cases. Suppose the ostrich, in the burning soil of Africa, fabricated

act be a wise one? Certainly not; for, in the first place, it would be an act not necessary; and in the next, it would probably be fatal to her young-they would risk being smothered in the place made for them. You are not therefore to accept in the literal sense the allusions in the 39th chapter of Job, to the ostrich, "which "leaveth her eggs in the earth, and warmeth "them in the dust, and forgetteth that the foot 66 may crush them, or that the wild beast may “break them. She is hardened against her "young ones, as though they were not hers; "her labour is in vain, without fear; because "God hath deprived her of wisdom, neither hath he imparted to her understanding."

Now, many animals take no care whatever of their young, but in no instance does this proceed from ignorance; for in every example where it happens, we shall find that the young do not want any care of the parent, and indeed that the latter could not be of any service to them. Up to the point, however, where knowledge is requisite for the continuance of the species, we find an admirable instinct guiding the parent, and precisely to that necessary point, but no farther. We have already adverted to the instinct which directs the butterfly to lay her eggs on the under side of a cabbage

leaf; and what could she possibly do more for them? it is all that is required or useful, and she performs the task most dutifully. The ostrich does the same, she does all that is necessary; she builds no nest, for that is not requisite; a shallow cavity scratched on the ground is all that is wanted, and that she makes.

Though this bird cannot fly, it can run with extraordinary swiftness, and is in all respects perfectly adapted to the vast deserts which it inhabits. This swiftness of foot enables it to extend its search very far in quest of food, and had it the instinct of sitting on its eggs day and night, it would perish of hunger; for the wildernesses, which are its natural abode, are in general thinly clothed with the vegetables which form its food. But though it roams abroad, and may be absent from its eggs for hours, still it has not forgotten them. The crocodile, when she has covered her eggs in the sand, thinks no more of them, for it is not necessary that she should; but the young ostrich requires a parent's care till it can provide for itself; and, according to the testimony of many travellers, the ostrich in reality, so far from being a careless, is a most attentive mother.

When away on her long excursions for food,