112 A PHILOSOPHER WITH NATURE 



sidles up to the other occupants of the nest, using as 

 feelers the long and bare wing processes, which have 

 an appearance strangely suggestive of the arms of 

 an ape. Getting gradually under its fellow-nestling, 

 it lifts it on to the flat back ; then using the ape- 

 like arms as props and the strong legs as levers, it 

 partly raises and partly pushes the victim upwards, 

 clambering backwards up the side of the nest. 

 When it reaches the edge the victim is hitched over 

 and the last scene of all almost takes one's breath 

 away, for the blind little creature, before returning 

 to the bottom of the nest, feels round as if to assure 

 itself that the difficult business had been in all 

 respects successfully accomplished. After its efforts 

 the cuckoo appears completely exhausted. But 

 it resumes its attempts when rested, and it will 

 continue for days to eject any other birds or eggs 

 that may be placed with it in the nest. 



The number of the theories which have been put 

 forward from time to time to account for the 

 unusual habits of the cuckoo is legion. The instinct 

 of the young bird is surprising enough in itself, but 

 the disappearance of the parental instinct in the 

 old bird, the habit of depositing its eggs in the nests 

 of other birds, the extraordinary variability of the 

 egg and the character of the nest in which it is 

 placed, appear to be quite as difficult to explain. 



One of the theories respecting the cuckoo which 

 has received general support is that the bird's 

 parasitic habits are the natural result of the character 

 of its food. This matter has an interesting aspect. 

 Those who are familiar with the natural selection 

 theories of Darwin, Wallace, and Lubbock will 

 know that certain hairy caterpillars are supposed 



