英文科學(xué)讀本 第二冊(cè)·Lesson 24 The Cow

Lesson 24 The Cow

Suppose, Norah, you tell us all you know about the cow.

Very well, said Norah, "I'll begin by saying that the cow is a large thickset animal, with short, stout, strong legs, just fit to support so heavy a body. It has a thick skin, which we call a hide, and the hide is covered with close smooth hair. It has a pair of smooth, pointed horns, and large broad ears, and its eyes are large and gentle looking."

Now I think that's very good for a little girl, said Willie. "Suppose we begin, Fred."

All right, said Fred, "we'll have a look at the feet. The cow's foot is just like the sheep's foot. It has four toes, but it walks only on the two front ones. The two short toes behind never touch the ground.

Each toe is covered with a hard, horny case, which we call a hoof. The foot looks as if it were split or cloven in two. We call it a cloven hoof. Now I want to ask a question. What do you remember about the animals that have cloven hoofs?"

They chew the cud, said Norah. "They do," said Will. "Suppose you tell us all about it, Fred."

Well, you remember that these animals have four stomachs, said Fred. "When they are feeding, they bite off and swallow the grass, till they have filled the first stomach, or paunch. From the paunch the grass is sent into a second bag or pouch, which has little hollows all round its sides. The grass collects in little cuds or pellets in these hollows, and the cuds are passed up into the mouth to be chewed. When it is chewed enough it is swallowed again. But it goes into a third stomach now, and from this is passed on to the fourth stomach to be digested.

Now just a word about the teeth of these cudchewers. What do you remember about the sheep's teeth, Norah?

It has no teeth at all in front of the upper jaw, only a thick, hard pad.

Right, said Fred. "Then, too, the back teeth have broad, flat crowns, and the lower jaw moves from side to side, as well as up and down. These teeth are called grinders. They have to crush and grind up the food as in a mill."

Quite right, said Fred. "Now don't forget, Norah, that the cow is exactly like the sheep in all these things."

SUMMARY

The cow chews the cud. Like the sheep, it has a hard pad, instead of teeth, in the front of the upper jaw, and great broad teeth for grinding and chewing. It has four stomachs. It fills its paunch with grass, which it swallows mouthful by mouthful, without chewing it. The paunch passes the food into a second stomach, and this sends it up into the mouth, in cuds, to be chewed, after which it is swallowed again. The cow has a cloven hoof, exactly like that of the sheep. It touches the ground with only two toes in walking.