MOTHS AND BUTTERFLIES. 



459 



beech, oak, walnut, maple, willow, and plum. The full-grown caterpillar is not more 

 than two inches in length when at rest, and three when in motion, pale bluish-green 

 with a pearl-colored head. It has a pale yellow stripe along- 

 each side of the body, and a transverse yellow line between the 

 segments of the back. There are five or six small pearly 

 tubercles on each segment, tinged with purple or red, and 

 having a few hairs. When mature it descends to the ground, 

 when it draws together a few leaves, and spins an oval, very 

 compact and strong cocoon of white or yellowish silk. It has 

 been said that the cocoons are spun in the trees, and fall to the 

 ground with the leaves in the autumn. They remain in this 

 state all winter, and emerge the next summer, there being but 

 one brood in a year. The silk from the cocoon of this moth 

 is of but little value, from the fact that it has never been reeled, 

 and probably never can be ; yet it would doubtless be of some 

 value as carded silk. 



The mulberry silk-worm, Bombyx mori, has been, without 

 doubt, the most useful to mankind of all insects, furnishing em- 

 ployment to vast numbers of people in different countries in 

 raising the worms and obtaining the cocoons, and to others in 

 manufacturing the silk into such varied and beautiful fabrics as 

 are offered both for our comfort and adornment. This species 

 has been cultivated in China, for the silk, from time immemorial ; 

 and the caterpillar in its wild state is now unknown, though it 

 may yet be found in that country. This insect was not intro- 

 duced into Europe until A. D. 550, and then only by stealth ; 

 for the inhabitants of China and southern Asia would not per- 

 mit them to be taken out of the country. Two monks are said 

 to have brought away the eggs concealed in their canes, and in- 

 troduced them into Constantinople, from which place they were 

 later taken into other parts of southern Europe. It was not 

 till the latter part of the sixteenth century, or early in the seven- 

 teenth, that an attempt was made to introduce this silk-worm 

 into America where it has been cultivated with varying success 

 down to the present time. Aside from its natural food plant, 

 the mulberry, it thrives well in this country on the leaves of 

 Osage orange, thus making it possible to cultivate them in por- 

 tions of the country where it otherwise would be impracticable. 

 This insect has been cultivated so long, and carried by man to 

 so many different countries, and reared under such diverse cir- 

 cumstances, that it may be considered not only completely 

 domesticated, but so many different races have been obtained, 

 that we are really in doubt what the exact characteristics of 

 the original stock may have been. 



The eggs are nearly round, yellow when first laid, changing to a slate or gray color, 

 and fastened by an adhesive substance which the moth secretes at the time the eggs 

 are laid. Each female lays three hundred or more eggs. The young caterpillars are 

 black or dark gray, and clothed with long, stiff hairs which arise from pale tubercles 



FIG. 577. Anatomy of 

 silk-worm. 



