THE SILK-WORM. 113 



straight, and end in knobs ; those of the moth curve, 

 and in nearly all cases are without knobs. Butterfly- 

 caterpillars spin a little; moth-caterpillars spin much 

 more. Some of them make their pupa cases, or co- 

 coons, entirely of silk. 



Moths usually wear sober colors. Some are very 

 gay and brilliant. Some are large, and others are very 

 small. The great owl moth of Brazil measures nearly 

 a foot between the tips of its wings. Our little clothes- 

 moth expands scarcely a half inch. Some moth-cat- 

 erpillars are smooth. Others are covered with bristles 

 or spines; stiil others emit an offensive odor all for 

 protection against their enemies. 



Moths are more destructive than butterflies. The 

 clothes-moth feeds on woolen and furs. The canker 

 worm eats the leaves of cherry, plum, and elm. The 

 tussock-moth-caterpillar preys upon pear and apple 

 trees. The fall web-worm allows very few trees to es- 

 cape its mischievous horny jaws. The tomato-worm, 

 the tobacco-worm, the cotton-worm are great destroy- 

 ers. And all these so-called "worms" are the cater- 

 pillars of moths. There is one moth-caterpillar, how- 

 ever, whose destruction is turned to good account, and 

 a short history of it must be given. 



It is the mulberry silk-worm, so called because its 

 favorite food is the mulberry-tree. Not our native 

 tree of that name, but the imported white mulberry. 

 Prof. Riley, of Washington, has, for nearly fifteen years, 

 kept silk-worms on the leaves of the common osage 

 orange ; and their silk proved to be of excellent quality. 

 This moth-caterpillar has a wonderful history, reach- 

 ing back, it is thought, as far as two thousand years 



L. C. 8. 



