terj)illaror larva state, is till the mouth of 

 July, during the first luxuriant growth of 

 the tree. It then changes into a pupa 

 which is Inirder and more dry than the 

 caterpillar ; in this state it is confined in a 

 narrow compass, and becomes surrounded 

 by a kind of web termed a chrysalis, that 

 issues from its mouth, and which on being 

 wound oft' is the raw silk, but in some 

 other species it is surrounded by a hard 

 impervious coat, scarcely to be penetrated 

 by tlie sharpest instrument, or to be acted 

 on by the most corrosive liquid. When 

 the insect has escaped from this state of 

 torpidity, in which it lies for different 

 periods*, it becomes the perfect fly, and 

 is then fit to fulfil the principal functions 

 to which all nature is devoted, the re- 

 production of the species. 



* One extraordinary circumstance attending this 

 race of creatures is the length of time some of the 

 species will remain alivein the pupastate; I released 

 one from a chrysalis this last summer, which had been 

 fixed to a wooden label in the Botanic (iarden, and 

 had been paijited over for eiglit years. There is a 



