live upon legs?

the earth that have not four

C. I think not; they have all four legs; except worms and insects, and such things.

F. You remember, I suppose, what an animal is called that has four legs; you have it in your little books? C. A quadruped.

F. A horse then is a quadruped: by this we distinguish him from birds, fishes, and insects.

C. And from men.

F. True; but if you had been talking about birds, you would not have found it so easy to distinguish them.

C. How so? a man is not at all like a bird.

F. Yet an ancient philosopher could find no way to distinguish them, but by calling man a two-legged animal without feathers.

C. I think he was very silly; they are not at all alike, though they have both two legs.

F. Another ancient philosopher, called Diogenes, was of your opinion. He stripped a cock of his feathers, and turned him into the school where Plato, that was his name, was teaching, and said, Here is Plato's man for you.

C. I wish I had been there, I should have laughed very much.

F. Probably. Before we laugh at others, however, let us see what we can do ourselves. We have not yet found any thing which will distinguish a horse from an elephant, or from a Norway

rat.

C. O, that is easy enough. An elephant is very large, and a rat is very small; a horse is neither large nor small.

F. Before we go any further, look what is settled on the skirt of your coat.

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 you?
C. No, that it is not.

F. Yet you called the butterfly large, and you called the rat small.

C. It is very large for a butterfly.

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, therefore, 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 variety 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 may add shape, though they are not

I

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 Of which division is the

digitated. horse?

C. He is hoofed.

F. There are a great many different kinds of horses; did you ever know one that was not hoofed?

C. No, never.