those who are not interested in the abstruse problems of the 

 mechanism of bird's flight, will find that comparisons made 

 between birds, bats, butterflies, and beetles when on the 

 wing are immensely interesting, and help to bring out the 

 peculiarities of each. 



During the twilight hours of a still summer evening one 

 may compare, with advantage, the rushing swoop of the 

 screaming swift, borne with lightning speed upon long, 

 ribbon-like pinions, with the curiously erratic flight of the 

 woolly bat with beaded eyes, who has ventured abroad for 

 his evening meal. One cannot but feel astonishment at the 

 marvellous dexterity with which he twists and turns, now 

 shooting up into the sky, now darting downward. What 

 bird can beat him, or even match him, in the art of doubling 

 back on his tracks ? And one can put his skill at lightning 

 turns to the test if one attempts to catch him in a butterfly 

 net. Often indeed have I attempted this feat, but never yet 

 with success. 



In the glare of noon-day this aerial athlete may perhaps 

 be found in a deep slumber, hanging head downwards behind 

 the shutters of a cottage window, or in some crevice of a barn- 

 roof. Gently seize him and as gently stretch out his wing. 

 The moment one opens it one sees that it is constructed upon 

 a totally different plan from that of a bird. In the first 

 place a thin membrane, or fold of skin, is seen to take the 



