THE INSTINCT OF ANIMALS 157 



Some years ago it was my good fortune to rear 

 from the beginning a specimen of the young of the 

 common cuckoo. The habits of this migratory bird, 

 which is a spring visitor in Europe, though it is not 

 found on the North American continent, are well 

 known by repute. The female lays her eggs in the 

 nests of small birds, and the young cuckoo, when 

 only a few days old, and while it is yet blind and 

 almost naked, ejects from the nest, with a purposive- 

 ness which is almost uncanny to watch, its fellow- 

 nestlings, and receives thereafter the sole care of 

 its foster-parents. As my young cuckoo became 

 full-grown, the degree of complexity and perfection 

 obtained by nature in mechanically attuning this 

 bird to the wants of its curious migratory Hfe was 

 extraordinary to witness, and made an unusual 

 impression on my mind. The cuckoo, it may be 

 mentioned, travels, in its annual migrations, enor- 

 mous distances over land and sea, sometimes from 

 the extreme north of Europe, across the equator, 

 into the Southern Hemisphere. In this case there 

 is no room for thinking that the young birds find 

 their way as the result of any teaching from the 

 older birds, for these leave many weeks later than 

 the older birds, and so travel apart. 



As the season waned, and the time for the migra- 

 tion of my young cuckoo approached and passed, 

 its behaviour grew interesting. The bird always 

 became very restless in the evening. Being much 

 attached to me, it generally settled at last, so as to 

 be near me, on the stationery case on the table on 

 which I was writing, in the dim light thrown by the 

 upper surface of the green shade of the reading-lamp 

 by which I worked. Here, as the hours wore on, 



