98 GROWTH OF THE CATERPILLAR. 



Of course so large a number is not necessary for 

 ordinary purposes; but tbis regiment was required 

 for the purpose of watching the development and 

 anatomy of the creature througb its entire life. 



As the skins of caterpillars are not capable of 

 growth, and the creature itself grows with singular 

 rapidity, it is evident that the skins themselves must 

 be changed, as is the case with many other animals 

 of a higher class, such as the snakes, newts, &c. 



JPor this purpose the skin of the caterpillar splits 

 along the back of the neck, and by degrees the crea- 

 ture emerges, soft, moist, and helpless. A very short 

 time suffices for the hardening of the new envelope ; 

 and as the caterpillar has been obliged to fast for 

 a day or two, previously to changing the skin, it sets 

 to work to make up for lost time, and does make up 

 effectually. 



In the case of the "Woolly Bear, and several others^ 

 the cast skin retains nearly the same shape and 

 appearance as when it formed the living envelope of 

 the caterpillar ; and, consequently, if any number of 

 these insects are kept, the interior of their habitation 

 soon becomes peopled with these imitation cater- 

 pillars. Bach individual changes its skin some ten 

 or eleven times, each time leaving behind it a model 

 of its former self, so that caterpillars seem to multiply 

 almost miraculously. 



Although even the exterior appearance of an insect 

 is very wonderful, yet its interior anatomy is, if pos- 



