Page:Popular Science Monthly Volume 3.djvu/677

Rh agriculture, industry, commerce; the producer and the artisan, the laborer in the fields, and the laborer in towns. Our caterpillar and its products will find a place in the elaborate treatises of statesmen; and a time will come when France will think herself happy that the sovereign of a distant empire, some four thousand leagues away, had been pleased to permit her to buy in his states, and pay very dear for, the eggs of this caterpillar"—you would abruptly turn your back and say, "This man is a fool." And you would not be alone: agriculturists, manufacturers, bankers, and officials, could not find sarcasms enough for this poor dreamer.

And yet it is the dreamer who is in the right. He has not traced a picture of fancy. The caterpillar exists, and I do not exaggerate the importance of this humble insect, which plays a part so superior to what seemed to have fallen to it. It is this of which I wish to give you the history.

Let us first rapidly observe this animal, within and without. We call it a silk-worm, but I have told you it was a caterpillar. (Fig. 7.) I add that it has nothing marked in its appearance. It is larger than the caterpillars that habitually prey upon our fruit-trees, but smaller than the magnificent pearl-blue caterpillar so easy to find in the potato-field. Like all caterpillars, it is is transformed into a butterfly. To know the history of this species is to know the history of all others.

Here in these bottles are some adult silk-worms, but here also are some large pictures, where you will more easily follow the details that I shall point out, beginning with the exterior.

At one of the extremities of its long, almost cylindrical body (Fig. 7), we find the small head, provided with two jaws. These jaws do not move up and down, as in man and most animals that surround us, but laterally. All insects present the same arrangement.

The body is divided into rings, and you see some little black points placed on the side of each of these rings; these are the orifices of respiration. The air enters by these openings, and penetrates the canals that we shall presently find. ,

The silk-worm has ten pairs of feet. The three first pairs are called the true feet, or scaly feet; the five last, placed behind, are the false feet, or the membranous feet. These are destined to disappear at length.

Let us pass to the interior of the body. Here we find, at first, the digestive tube, which extends from one extremity to the other. It commences at the œsophagus, that which you call the throat. Below you remark an enormous cylindrical sac; it is the stomach, which is followed by the very short intestine. These canals, slender and tortuous, placed on the side, represent, at the same time, the liver and kidneys. This great yellow cord is the very important organ in which is secreted the silky material (Fig. 2). In proportion as the animal