MOTIONS OF INSECTS. 



299 



Towards sunset the common Ephemerae (E. vulgata), dis- 

 tinguished by their spotted wings and three long tails (cau- 

 dulce), 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 ; when 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. 1 Our most common species, which I have usually 

 taken for the E. vulgata, varies from that of De Geer in its 

 proceedings. I found them at the end of May dancing over 

 the meadows, not over the trees, at a much earlier hour — at 

 half-past three — rising in the way just described, about a 

 foot, and then descending, at the distance of about four or 

 five feet from the ground. Another species, common here, 

 rises seven or eight feet. I have also seen Ephemerse flying 

 over the water in a horizontal direction. The females are 

 sometimes in the air, when the males seize them, and they 

 fly paired. These insects seem to use their fore-legs to break 

 the air ; they are applied together before the head, and look 

 like antennae. — Hilara maura, a little beaked fly, I have ob- 

 served rushing in infinite numbers like a shower of rain 

 driven by the wind, as before observed, over waters, and 

 then returning back. 



It is remarkable that the smaller Tipularice will fly un- 

 wetted in a heavy shower of rain, as I have often observed. 

 How keen must be their sight, and how rapid their motions, 

 to enable them to steer between drops bigger than their own 

 bodies, which, if they fell upon them, must dash them to the 

 ground ! 



i De Geer, ii. 638. 



