VARYING COLOUR OF CUCKOO'S EGGS 139 



the Ibis of April, 1889. What has once taken 

 place may happen again. 



In the back of the young cuckoo there is a 

 curious depression, and scientists have asserted 

 that this is a provision of Nature to enable the 

 young bird to eject the other eggs which are in 

 the nest, a theory which I find it difficult to 

 accept, though unable to suggest any other 

 reason for this conformation. It is commonly 

 believed that the cuckoo actually lays its egg in 

 the nest which it may select for the purpose, 

 Now, when the size of the bird is compared with 

 that of the nests in which it is known to deposit 

 its egg, and also when the shape of some of these 

 nests is considered, it will be seen at once how 

 impracticable such a performance must be. The 

 egg is without doubt placed in the nest, the 

 bird carrying it in its bill for the purpose, an 

 operation for which the latter is peculiarly well 

 adapted. 



An acquaintance of mine living in Hampshire, 

 a student of ornithology, stated in the Field some 

 few years ago the names of the different birds in 

 whose nests he had from time to time discovered 

 the eggs of the cuckoo. The list was a long one, 

 thereby proving his research, but what seemed 

 most worthy of note was his assertion that he had 

 observed that the colour of the egg invariably 

 partook very much of that of the other eggs in 

 the nest ; for instance, if the egg was found in 

 that of a robin, its general tone was reddish ; if in 



