194 BERTHA'S VISIT TO HER 



destroyed in a still larger proportion. This is 

 one of the innumerable instances of the goodness 

 of Providence, which balances the necessary evils 

 of one tribe of animals by the instinctive efforts 

 of another. 



My aunt tOld me, that in St. Domingo the 

 cassada and indigo plantations are materially in- 

 jured by a large caterpillar. When it changes 

 to its last robe of sea-green, its tortures begin ; 

 a swarm of ichneumon flies fasten themselves all 

 over the poor victim, drive their stings into 

 the skin, and then deposit their eggs in the 

 wounds they have made. The caterpillar swells 

 and becomes of a deeper green, and in a fort- 

 night, when the eggs are hatched, it appears co- 

 vered with little worms, which start out of every 

 pore. The existence of these worms is but short; 

 after raising themselves on one end, shaking 

 their heads, and swinging themselves in every 

 direction, each of them begins to form its co- 

 coon ; and in two hours the caterpillar is com- 

 pletely clothed in a white robe. In eight days 

 the ichneumon flies are hatched, and the little 

 cocoons they leave behind are composed of a 

 very fine silky cotton of the most dazzling 

 whiteness, which may be used without any 

 preparation, as soon as the flies have quitted 

 them. 



The quantity of this glossy substance, pro- 

 duced by the millions of those little parasites, is 



