vi HABITS OF THE CUCKOO 259 



its own eggs, as conversely the American cuckoo now only 

 occasionally lays its eggs in other nests. Who can prove 

 that reflection did not underlie this difference of action, 

 determining it according to the different conditions ? For the 

 cuckoo certainly shows reflection in its choice of nests in 

 which to lay its eggs, and in many other actions. But 

 whether our cuckoo acts at the present day from pure instinct 

 or still by reflection even assuming the first it is, I believe, 

 necessary, in order to explain the instinct, to start from the 

 supposition that it has arisen by the inheritance of habit 

 originally intelligent. The conditions of life of the bird enable 

 us to understand easily enough the ultimate causes of the habit. 

 The cuckoo lives the life of a vagabond. It wanders about 

 restlessly ; in the first place, it remains with us only a few 

 months, from April to August; secondly, even in the region 

 where it settles here it has no permanent station, it wanders 

 now in one direction now in another. This restlessness is 

 caused by its insatiable appetite and sexual desires. It is 

 ever seeking food and mates. Its food consists principally of 

 caterpillars, especially those which, like Gastropacha pini, 

 occur only here and there in great abundance. The cuckoo 

 must therefore move about in order to satisfy its need of food. 

 When it has found a swarm of caterpillars it revels in excess, 

 and its sexual requirements are increased. It enjoys on 

 account of its loose life the worst of reputations ; the bonds 

 of marriage are unknown to it, especially to the lady-cuckoo. 

 Brehm says of it, with regard to this : " Any one who doubts 

 the intense lustfulness of the cuckoo needs only to visit its 

 sleeping-places repeatedly. To-day are heard the voice of the 

 female, the soft wooing of the male ; to-morrow only the cry 

 of the latter ; the former is then blessing a neighbour or a 

 distant mate." l Farther on : " Although he meets with no 

 reluctance, desire seems to drive him out of his senses. He 



1 Brehm, Illustr. Thierleben, second edition, vol. iv. p. 215. 



