THE WINTER REST. 103 



The creatures wliich subsist exclusively or 

 iiiiiinly upon suiall gnats and other flying insects 

 are of course those upon which the winter rest 

 tells most unfavorably. The swallows and mar- 

 tins indeed, whose beautiful, curved flight, open- 

 mouthed, over the ponds and fields where such 

 insects abound is one of the most charming sights 

 of summer, evade the difliculty by retiring to some 

 of the now fiishionable winter stations in Georgia 

 and the Gulf, on the Riviera or in Andalusia, and 

 Algeria, where they may hawk to their hearts* 

 content itfter flies and mosquitoes the whole win- 

 ter through. But the less fortunate bats have 

 never learned, or inherited from their ancestoi-s, 

 this convenient device of migration ; and they are 

 consequently compelled to hide in the roofs of 

 houses, the steeples of churches, and the crevices 

 of rocks, as soon as the midges have disappeared 

 for the season, and there to sleep away the foo<l- 

 less period in a state of complete torpidity. Lack 

 of food, in short, is everywhere the great cause of 

 the winter torpor. For example, hibernation is 

 comjjaratively very rare among birds, but the owl 

 may almost be said to hibernate, for during the chil- 

 liest months, when shrews, field-mice, water-rats, 

 and voles — its favorite prey — are all laid up in 

 their various winter beds, it often goes for weeks 

 together without [)ro vender, and seems then to 

 doze away the time in a practically dormant and 



