138 NATURAL HISTORY. 



very strong, particularly at the ends. They lay their 

 eggs in the water, where both larvae and numphae remain 

 for many months before their perfect development. In 

 the first two states and living in the water, they resemble 

 the perfect insect, except that they have six feet and no 

 wings. They change early into pupae ; this second stage 

 of their being is only distinguished from the first by 

 indications of the rudiments of four wings and a larger 

 growth. Most of the libellulse are of a brownish-green 

 color ; head, breast, and abdomen distinctly separated ; 

 they swim well and respire water by means of a lamellar 

 appendage at the posterior extremity of the body. After 

 remaining ten or eleven months in the water, the pupa 

 leaves it and climbs upon a plant, where it awaits its 

 final transformation. After remaining motionless for a 

 time, the skin on the breast begins to separate, and the 

 perfect insect slowly issues from its envelope, unfolds its 

 wings, which at first are humid and soft, to be dried by 

 the air, a process which frequently requires two hours 

 for its completion. The different species of dragon-flies 

 can not, as in most other insects, be distinguished by the 

 color. The race, however, is divided into the following 

 families : 



1. The Broad Dragon Fly, with round head and 

 broad hinder body, carrying the wings horizontally ex- 

 tended. 



The Common Dragon Fly (libellula vulgata), yel- 

 low-gray or reddish ; wings altogether diaphanous, body 

 cylindrical. 



The Yellow Adder-bolt (libellula depressa). The 

 males have the aklomen spear-shaped, and of a fine 

 blue color. In the females the sides are spotted, and 



