THE COTTON-WQftM. 141 



days. The number of eggs deposited by the female is un 

 certain ; they are smaller than a mustard seed, and always de- 

 posited on the under surface of the leaf during the night ; in 

 a few days their eggs hatch. The worm, at first a minute 

 living point, falls immediately to work to devour the leaf; its 

 growth is rapid, for its labors cease not night nor day until it 

 arrives at maturity ; it then winds itself up in a leaf by 

 means of a 'web resembling a cobweb, casts its skin and 

 changes into a chrysalis, in which state it remains ten days, 

 then it bursts the thin walls of the chrysalis, and comes forth a 

 perfect insect. In turn, it begins the work of reproduction, 

 deposits its eggs, and in ten more days it dies. 



Thus in every ten days there is an additional generation, 

 and they go on increasing ad infinitum. As soon as the leaves 

 were consumed in a field this great army took up its march : 

 some in search of comfortable quarters, where they might re- 

 pose from their labors ; others on a foraging expedition to re- 

 plenish the means of their subsistence. The first took shelter 

 in the first leaf they met with, but generally they proceeded 

 as far as the fence, a barrier beyond which they never trav- 

 elled, where they found a plentiful supply of leaves, in which 

 they enveloped themselves. The second division extended 

 their march much farther, sometimes travelling half a mile 

 from the point whence they started, perishing by cart-loads 

 for the want of food and the many casualties to which their 

 journey subjected them, such as carriage wheels, heat of the 

 sun, and the rapacity of birds. 



Here then it would appear was an end of the cotton-worm 

 for a season at least; for those which yet remain in chrysalis 

 in the fence-corners, will change to the fly in ten days. But 

 where are now the cotton leaves upon which the pregnant fe- 

 male is to deposit her eggs ? There is not one left. If they 

 are placed on any other leaf the eggs may hatch, but the 



