80 



NATURAL HISTORY. 



[CH. IV. 



Those worms which have recently shed their 

 skin are easily known from the others, by the pale 

 colour and wrinkled appearance of their new skin. 

 The larva changes its skin five separate times ; and, 

 on each occasion, increases in size and weight, as 

 may be seen in the following table : 



Thus, in the space of a few short weeks, the 

 worm increases in weight more than nine thousand 

 times. 



The annexed figures represent the worm in its 

 last stage, the chrysalis, and the cocoon. 



The caterpillar, having arrived at its last moult, 

 devours its food most voraciously, and for ten days 

 continues increasing in size ; so that its structure 

 can be better explained than in its former stages. 

 It is now about three inches in length, and is com- 



