MOTHS AND BUTTERFLIES. 187 



ger. On this account, these caterpillars have been 

 called by the common people, tailors, and by others, 

 geometrae, or surveyors. Those caterpillars which 

 have only four pairs of feet, are able to stand erect on 

 their hind feet for hours, forming an acute or a right- 

 angle, and in this motionless position resembling a 

 little twig of the shrub or tree upon which they are 

 standing. 



Caterpillars are generally covered with very hand- 

 some colors, and even the plainest looking will appear 

 handsome upon a close examination with a magnify- 

 ing glass. The size of their bodies varies very much in 

 proportion to the size of the perfect insect, and their 

 exterior surface is either smooth, as that of the Aste- 

 rias on the parsnip, Plate VI. Fig. 30, or that of the 

 Danaus on the milk-weed, or it is hairy like that of 

 the Saturnia, Plate VI. Fig. 27, on Indian Corn and 

 other grasses. 



The food of caterpillars, with a few exceptions, is 

 taken from the vegetable kingdom. Some feed ex- 

 clusively on one species of plant, as the silk-worm on 

 the white mulberry : others on all the species of one 

 genus, as the potatoe worm on the tomato, potatoe, &c. : 

 others eat any kind of vegetable, as the woolly-bear, 

 (Arctia.) The periods of taking their meals is also dif- 

 ferent; some eat only in the morning and evening ; 

 others during the whole day, and others only at night 



