bers of them run. Almost all the predaceous tribes, such as the black dors, clocks, or ground beetles, are gifted with uncommon powers of motion, and run with great rapidity. Ants are also remarkable for their velocity; and so are some species of lice and mites. Some flies too, are extremely difficult to take, from their very great agility. Mr. Delisle observed one, so minute as to be scarcely visible, which ran nearly three inches in a demi-second, and in that space made 540 steps; which is equal to the pace of a man who should run at the incredible rate of more than twenty miles in a minute.

Many of the jumpers among them perform exploits equally wonderful. Locusts and fleas, will, it is said, leap to a height equal to two hundred times their own length; and the cicada spumaria, or froth insect, which in general lies quietly under its frothy covering, on the stalks of plants, will sometimes jump five or six feet, which is more than two hundred and fifty times its own length.

HENRY.-Astonishing! Why it is as if a man should be able at once to vault through the air to the distance of a quarter of a mile! It reduces the wonderful exploits of the Grecian athlete into very insignificant performances. Insects must possess very great strength to be able to exert such agility.

PAPA.—They do. I think it has been computed that the strength of the beetle is, bulk for bulk, a thousand times that of a man.

ANNA. It is well for us, papa, that they are such little creatures then; if they were as big as men, how tremendous they would be!

PAPA. They would indeed. Here is another of the jumpers, Anna, you would not suppose it from the appearance of its legs.

ANNA. No, Papa, that I should not. How uncommonly short they are!

PAPA. This is one of the elastic beetles, or skip-jacks, as some call them. Its legs are so short, that if it hap

pen, by any chance, to roll upon its back, it cannot possibly turn round and regain a prone position: it is therefore furnished with a mechanism, by means of which, it sometimes throws itself an inch or two into the air, and in coming down again, it manages to regain its legs. So that you see legs are not the only organs by which even perfect insects leap.

ANNA. The leaping of Insects is very wonderful, certainly; but do you know, Papa, it is not so astonishing to me as their climbing. I cannot conceive how they manage to run up, not only a perpendicular surface, even if it be glass, but also to walk on the ceiling as many of them do.

PAPA. It is, my dear, as you say, a subject that affords room for much interesting and curious enquiry, since many of them have the power of moving against gravity, and can "tread the ceiling, an inverted floor.".

Climbing insects may be divided into three classesthose that climb by means of their claws:-those that climb by a soft cushion of dense hair, which lines the underside of the joints of their feet:-and those that climb by the aid of suckers, which adhere (a vacuum being produced between them and the substance they tread upon) by the pressure of the atmosphere. Here is the drawing of a beetle's leg magnified, which may give you an idea of the implements with which the first class of climbers is furnished; a class which includes a large proportion of insects, especially of the coleoptera order. You see the tarsus, or foot, terminates in a double claw, which is employed to great advantage in crawling or running over rough surfaces.

ANNA.-Beetles cannot run upon glass, I think; for I saw one on the window the other day, and as often as it attempted to move, it fell down..

PAPA.-No, I dare say it could not run upon glass; for as its hooks could find nothing on such a hard, smooth surface to take hold of, they rather impeded, than assisted its course. If it had had the soft cushion of thick

hairs, as many of the beetle tribe, and all the weevils have, it would, in all probability, have succeeded better.

The most remarkable class of climbers, consists, I think, of those that are furnished with suckers; which are thin membranes, capable of great extension and contraction, and which enable them to adhere, with the greatest safety, not only to the walls and windows, but also to the ceilings of our rooms. The common house-fly is a familiar example of this: it has two such suckers, connected with the last joint of the tarsus; by means of which, it takes its repose on the ceiling of a room with as much ease, and with more safety, than it could do on the floor.

ANNA.-I do not, Papa, quite understand, how these suckers enable them to do so.

PAPA. The suckers, my dear, act, as I hinted before, by producing a vacuum; that is, by expelling the air. You remember laying your hand on the air pump when I was working it the other day, and that when the air underneath it was all exhausted or drawn off, you could not move it.

ANNA.-Yes; and I recollect you told me that the reason why I could not move my hand, was that there was a vacuum under it: I did not quite understand it then, but I think I do now; you meant that there was no air under it.

PAPA.-Exactly so: and therefore the column of air that was above it pressed it down. The fly's suckers act something like an air-pump; on the insect's alighting, they expel the air under its feet, when the external pressure of the atmosphere enables it to adhere firmly in any posture. It is their fixing these suckers that produces the stinging sensation which is felt, especially from gnats, when they alight upon you. You may see the manner in which they are used, by looking, with a common microscope, at the movements of a large bluebottle fly on the inside of a glass tumbler.

Conversation VII. to be continued.

46

LETTERS TO A YOUNG LADY

DEAR M.,

ON LEAVING SCHOOL.

LETTER THE TWELFTH.

You complain, with some reason, of the infrequency of my letters of late; I hope I shall now be more punctual. I am not offended, believe me, at that you doubt, whether, since you must begin the world without a knowledge of mankind, it is not safer to mistrust every one, at least till by experience you have gained a quicker insight into human character. My Love, there is but one standard of morality, that, apart from circumstance and under every circumstance alike, without reference to any individual law of God or man, without the ifs and the buts, and all the thousand subterfuges with which we justify ourselves in what we like, and excuse ourselves from what we like not, is always ready, always decisive, and always right—" Do to others as you would they should do to you." It is a precept to begin the world with, to go through it with, and to end it with. I would have you bind it about your heart and grave it upon your bosom; and whenever you hesitate on a question of conduct towards others, make recourse to it and abide by it. This, I think, will go far to decide the doubt between us. Entering on a world in which you are as yet a stranger, do you wish to be received in it with jealousy, suspicion, and reserve, till you have proved your claim to its confidence and good-will? I think not. And yet you conceive that you have a right in this manner to treat every stranger you meet with, for your own security. But while I counsel a feeling of universal kindness to begin with, it was to secure you from presumptuous confidence on the one hand, and cold suspicion on the other, that I advised you, in a

former letter, to make human nature, that is, your own nature, your especial study, in its varieties as well as in its general characters. I have given myself some trouble to examine what it is that makes women so much less just, candid, and liberal towards each other than men are; and I am persuaded that in part, at least, it arises from their attaching too much importance to little things, and falsely appreciating the comparative importance of greater ones, for want of an adequate knowledge of the human heart, and the springs and principles of human action. Just as, if women were sent to trade at the Horse Bazaar, they would value the horses by some very un-connoisseur fancies of their own, about the heads, and the tails, and the colours, &c., to the no small confusion of all honest dealing. But where are you to study human nature? There are but two-yes, there are three ways in which to study it-in books, in the living beings around you, and in yourself. And then what books? You see how well I guess your questions, without waiting the return of the post. In many and of many kinds. But there is one, my Love, above all others, that opens human nature to itself, and therefore I shall name it first. The authors of all other books have some bias of their own, which gives a colouring to their views of men-the Author of this book has none. Other writers can behold only what is exhibited without, and thence trace up the issues to their sourcea process that needs much judgment and experience, and is liable to perpetual error. The inditer of this only book beholds the source itself, not in one specimen or two, but in every individual of our race, and knows them entirely throughout. Aware that I speak of the Bible, you are eager to answer that this you have read, this you have studied from your youth up, therefore I need not be recommending it to you now as something new. I know that you have, and I am persuaded for a better purpose- that of becoming acquainted with your God and your eternal interests. But did you ever