THE rUPA OR CIIRYSALIS. 93 



little cocoon becomes eventually so hard that a 

 knife will scarcely make an incision in it. 



Aquatic larvae, such as that of the "Water Beetle, 

 Dyticus Marginalis, burrow in the banks at or 

 near the surface of the water, and there undergo 

 their change in a well-made cocoon of earth, which 

 they construct with much skill, and in which the 

 larva, gradually shortening and changing in all its 

 proportions, by degrees becomes a perfect Beetle 

 (during what Linnseus has termed the nymph state, 

 to distinguish it from that of the true chrysalis), 

 but it is still white and soft in all its members, even 

 more so than in the Caterpillar stage, till the hard- 

 ening process begins. Some of the earth cocoons, 

 or rather cases, of this kind are very compact and 

 hard ; others comparatively brittle and easily in- 

 jured. The aquatic larva of the Dragon-fly has the 

 faculty, as stated in another place, of preparing for 

 its future destiny by actually quitting its native 

 element, and preparing to undergo its change to 

 the pupa state, while clinging to a rush or reed 

 just above the surface of the water, but without 

 any protection whatever. 



The most interesting cocoons, and other pro- 

 tective habitations for undergoing the transforma- 

 tion to the pupa state, are those constructed by the 



