368 MOTIONS OF INSECTS. 



they are confined to the hardy Tipulariae. In the morn- 

 ing before twelve, the Hoplice, root-beetles before men- 

 tioned, have their dances in the air, and the solsti- 

 tial and common cockchafer appear in the evening the 

 former generally coming forth at the summer solstice 

 and fill the air over the trees and hedges with their 

 myriads and their hum. Other dancing insects resemble 

 moving columns each individual rising and falling in a 

 vertical line a certain space, and which will follow the 

 passing traveller often intent upon other business, and 

 all unconscious of his aerial companions for a consi- 

 derable distance. 



Towards sun-set the common Ephemerae (E. vulgata\ 

 distinguished by their spotted wings and three long 

 tails (Caudulae}) commence their dances in the meadows 

 near the rivers. They assemble in troops, consisting 

 sometimes of several hundreds, and keep rising and 

 falling continually, usually over some high tree. They 

 rise beating the air rapidly with their wings, till they 

 have ascended five or six feet above the tree ; then they 

 descend to it with their wings extended and motionless, 

 sailing like hawks, and having their three tails elevated, 

 and the lateral ones so separated as to form nearly a 

 right angle with the central one. These tails seem given 

 them to balance their bodies when they descend, which 

 they do in a horizontal position. This motion continues 

 two or three hours without ceasing, and commences in 

 fine clear weather about an hour before sun-set, lasting 

 till the copious falling of the dew compels them to retire 

 to their nocturnal station a . Our most common species, 

 a De Geer, ii. 638. 



