Silk-Worms and Giant Night-Butterflies 71 



they turn gray. When very young, the caterpillars 

 are a sort of yellowish green, with the last division 

 of their bodies, called the anal plate, of a bluish 

 tinge. The caterpillars feed on the leaves of the 

 oak, hickory and walnut, and I have seen them on 

 chestnut trees. They become fully grown by the 

 end of July. 



The larva is of a pale and very clear bluish- 

 green color. It has a yellow stripe on each side 

 of the body. It is addicted to warts, and there are 

 as many as six pearl-like warts of a purple or 

 rose color on each ring of its sausage-shaped 

 body; like the warts you often see on a person's 

 face, the ones on the caterpillar are furnished with 

 a few little hairs. When the caterpillar is not 

 stretching itself, it is nearly as thick as your 

 thumb ; it is then a short, stumpy creature, but when 

 walking it will stretch to three or more inches in 

 length. 



When kept in confinement, these caterpillars 

 are subject to a sort of spotted fever. Of times 

 black spots will appear on their bodies, and then 

 they will die. But if they live to the age of fifty- 

 five (days, not years) they will turn pinkish or 

 flesh-colored. 



