252 MENTAL EVOLUTION IN ANIMALS. 



First, there are the very numerous species of true Cuculus, 

 with its immediate sub-divisions, inhabitants chiefly of 

 Southern Asia, Africa, and Australia. Secondly, the crested 

 cuckoos (Coccystes), exemplified by C. glandarius, which is 

 common enough in Spain, and has been known to stray into 

 this country. This bird deposits its eggs in the nests of mag- 

 pies and crows. Another species (C. melanoleucus), which is 

 very common in India, selects for this purpose the nests of a 

 particularly noisy and familiar group of birds in that part of 

 the world, often called ' dirt-birds ' (Malacoccrcus) ; and as 

 the latter lay a spotless blue egg, similar in colour to that of 

 the hedge-chanter {Accentor modularis) of Europe, the egg of 

 the particular cuckoo which seeks their nests is of a nearly 

 similar spotless greenish-blue colour. Another very common 

 Indian bird of this family is the koel (Eudynamis orientalis), 

 the male of which is coal-black, with a ruby eye, and the 

 female beautifully speckled. A pair, in fine condition, may 

 now be seen in one of the aviaries in the Zoological Gardens. 

 The Indian koel invariably deposits its egg in a crow's nest, 

 and the egg is not unlike that of a crow in its colouring and 

 markings. Several other species of koel inhabit the Asiatic 

 islands, and there is one in Australia ; and as the koels are 

 not migratory birds, it follows that the parasitic habit is in- 

 dependent of any migratory necessity. That extraordinary 

 cuculine bird, the Australian channel-bill (Scythrops novw- 

 hollandice), is known to be parasitic, for the young have been 

 repeatedly seen tended and fed by birds of other species ; and 

 therefore it is a lapsus pcnnce on the part of Mr. Gould, in 

 his ' Handbook of the Birds of Australia,' describing a speci- 

 men of it as having been an 'incubating female!" But the 

 coucals (Centropus), very common and conspicuous birds in 

 Southern Asia, Africa, and Australia, are not parasitic ; 

 neither, we have reason to believe, are the extensive malkoha 

 series (Phamicophaus and kindred genera), which inhabit the 

 same geographical area. Among the American Cucididce, the 

 species of Coccyzus are nearly akin to the crested cuckoos 

 (Coccystes) of the major continent; and these, like the para- 

 sitic Cuculidce, produce their eggs at considerable intervals, 

 so that eggs and young of different ages are found in the 

 same nest ; while more advanced young, that had quitted the 

 nest, are still fed by their parents while keeping to the 

 immediate vicinity of the nest ; as may likewise be observed 



