MOTHS AND BUTTERFLIES. 



459 



m 



,iii., 



A> 



beeeli, 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 strijie 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, ;uid 



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



when it draws together a few leaves, and spins an oval, ver)- 



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



been said that the cocoons are spun in liie 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 jirobably never can be; yet it would doubtless be of some 



value as carded silk. 



The mulberry silk-worni, Bombijx mori, has been, without 

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

 ployment to vast iniuibers 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, thougli it 

 nuiy 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 jier- 

 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 otlier 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 mul!)eri-_y, it thrives well in this country on the leaves of 

 Osage orange, thus making it possilile to cultivate them in jior- 

 tions of the country where it otherwise would lie 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 wliich the motli 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 ])ale tubercles 



Fig. 



77. — Anatomy of 

 silk-worui. 



