you? C. It is a butterfly: what a prodigiously large one! I never saw such a one before. F. Is it larger than a rat think F. Yet you called the butterfly large, called the rat small. F. It is so. You see, therefore, that large and small are relative terms. C. I do not well understand that phrase. F. It means that they have no precise and determinate signification in themselves, but are applied differently. according to the other ideas which you join with them, and the different positions in which you view them. This butterfly, iherefore, is large, compared with those of its own species, and small compared with many other species of animals. Besides, there is no circumstance which varies more than the size of individuals. If you were to give an idea of a horse from its size, you would certainly say it was much bigger than a dog; yet if you take the smallest Shetland horse, and the largest Irish greyhound, you will find them very much upon a par : size, therefore, is not a circumstance by which you can accurately distinguish one animal from another; nor yet is colour. C. No; there are black horses, and bay, and white, and pied. F. But you have not seen that va. riety of colours, in a hare, for instance. C. No, a hare is always brown. F. Yet if you were to depend upon that cireumstance, you would not convey the idea of a hare to a mountaineer, or an inhabitant of Siberia ; for he sees them white as snow. We must, therefore, find out some circumstances that do not change like size and colour, and I may add shape, though they are not so obvious, nor perhaps so striking Look at the feet of quadrupeds; are they all alike? C. No: some have long taper claws, and some have thick clumsy feet without claws. F. The thick feet are horny ; are they not? C. Yes, I recollect they are called hoofs. F. And the feet that are not covered with horn, and are divided into claws, are called digitated, from digitus, a finger; because they are parted like fingers. Here, then, we have one grand division of quadrupeds into hoofed and digitated. Of which division is the horse ? C. He is hoofed. a kinds of horses ; did you ever know one that was not hoofed ? C. No, never. F. Do you think we run any hazard of a stranger telling us, Sir, horses are hoofed indeed in your country, but in mine, which is in a different climate, and where we feed them differently, they have claws ? C. No I dare say. not. I . F. Then we have got something to our purpose; a circumstance easily marked, which always belongs to the animal, under every variation of situation or treatment. But an ox is hoofed, and so is a sheep; we must distinguish still farther. You have often stood by, I suppose, while the smith was shoeing a horse. What kind of a hoof has he? C. It is round and all in one piece. F. A horse, then, is not only hoofed but whole-hoofed. Now how many quadrupeds do you think there are in the world that are whole-hoofed ? C. Indeed I do not know. F. There are, among all animals that we are acquainted with, either in this country or in any other, only the horse, the ass, and the zebra, which is a a species of wild ass. Now, therefore, you see we have nearly accomplished our purpose; we have only to distinguish him from the ass. C. That is easily done, I believe; I should be sorry if any body could mistake my little horse for an ass. F. It is not so easy, however, as you imagine; the eye readily distinguishes them by the air and general appearance, but naturalists have been rather puzzled to fix upon any specific difference, which may serve the purpose of a definition. Some have, therefore, fixed upon the ears, others on the mane and tail. What kind of ears has an ass ? C. O, very long clumsy ears. Asses' ears are always laughed at. |