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 
143 
