276 INSECTA. 



caterpillars are contented with connecting leaves, particles of earth, 

 or of the substances on which they have lived, and thus forming a 

 rude cocoon. The chrysalides of the Diurnal Lepidoptera, orna- 

 mented with golden spots, whence the term chrysalis, are naked, and 

 fixed by the posterior extremity of the body. The nymphs of the 

 Lepidoptera present a special character, of which Ave have spoken in 

 our general observations on the class of Insects. They are sxoathed 

 or resemble mummies *. Those of several Insects of this order, 

 particularly of the Diurnae, undergo their metamorphosis in a few 

 days; they even frequently produce two generations in the course of 

 the year. The caterpillars or chrysalides of others, however, remain 

 during the winter in one of those states, and only appear as perfect 

 Insects in the spring or summer of the following year. Generally 

 speaking, the eggs laid in the fall are not hatched till the ensuing 

 spring. The Lepidoptera issue from their envelope in the usual 

 manner, or through a slit which is effected on the back of the thorax. 



The intestine of caterpillars consists of a large tube without 

 flexures, of which the anterior portion is sometimes slightly sepa- 

 I'ated in the manner of a stomach, and the posterior forms a wrinkled 

 cloaca ; their four biliary vessels are very long and inserted very far 

 back. 



In the perfect Insect, we find a first lateral stomach or crop, a 

 second inflated or turgid stomach, and a tolerably long small intes- 

 tine, with a csecum near the cloaca f. 



The larvae of the Ichneumonides and Chalcidites deliver us from 

 a great portion of these destructive animals. 



We will divide this order into three families, which correspond to 

 the three genera of which it is composed in the system of Linnaeus, 



FAMILY L 



DIURNA. 



This family % is the only one in which the exterior margin of the 

 inferior wings does not present a rigid, squamous seta or kind of 

 bridle for retaining the two superior ones. These latter, and even 



* The sheaths of the legs and antennse are fixed, a character peculiar to this sort 

 of metamorphosis. 



f For the anatomy of the caterpillar, see the admirable work of Lyonet ; and 

 for the development of the organs in the chrysalis and butterfly, that of Herold, 

 entitled History of the development of Butter/lies, in German, Cassel and Marburg, 1815, 



:J; Some of the Nocturna excepted. 



For the genera of the Diurnal Lepidoptera, see the first numbers of the Descrip- 

 tive Catalogue of the Lepidoptera in the Museum of the East India Company, of 

 M, Horsfield. 



