168 COLIN CLOUT'S CALENDAR. 



movements than that ; but then each movement of the 

 swift is almost certainly conscious and voluntary. We 

 can hardly doubt that if clock-hands and fly-wheels 

 were both alive, a minute would seem a much longer 

 division of time to the fly-wheel than to the clock-hand. 

 It has been well said that in acute mania the nervous 

 organism is burning itself out too fast ; what is morbid 

 in the lunatic is normal and healthy in such a bird as the 

 swift. 



Swifts eat on the wing, drink on the wing, and collect 

 materials for their nest on the wing. Hence, like all 

 otjier very active creatures, they produce extremely small 

 broods ; for the material used up in muscular motion 

 cannot also be devoted to genesis as well. The nests 

 are usually rude unshapely structures, under the eaves 

 of churches or among the ruins of old buildings gener- 

 ally ; and only two eggs are usually laid by each mother 

 in a single season. It would be a curious question what 

 these haunters of old buildings did for a home before the 

 days of civilized man ; for 1 have never known them 

 build away from human habitations or churches. Per- 

 haps the species in its present form may really date later 

 than civilization, as one may suspect of many other creat- 

 ures, both weeds and house parasites, like geckos and 

 crickets ; for after all, even civilization is old enough to 

 have exercised some minor transforming influence upon 

 the outer shapes of organic beings, as it undoubtedly 

 has upon their habits and instincts. 



Long ago, Gilbert White was much puzzled with the 

 difficulty, suggested to him by the swifts, as to what 

 became of the annual increase which must take place 

 even among such small breeders as these ; for though 

 they lay but two eggs at a time, and sit but once each 

 Bumnier, instead of twice like the other swallows, yet 



