54 A NATURAL HISTORY OF THE CUCKOO. 
together as a higher group under the designation Cuculidez. From 
them, however, it is necessary to detach the Honey-guides ( Indica- 
tor) of Africa, which are much more nearly related to the Wood- 
peckers, approximating the Cuckoos only in secondary or superficial 
characters ; also the Courols ( Leptosomus) of Madagascar, which 
are more intimately allied to the Puff-birds of America ; the Rain 
Fowl (Scythrops) of New Holland, which, merely from having a 
great beak, and for no other reason whatever, has sometimes been 
placed among the Toucans, is, in every essential detail of its con- 
formation, a true Cuckoo. The degree of affinity which the West 
Indian Ani, also, bear to this group, must continue problematical, 
until we know something of their interior anatomy. 
As thus restricted, then, a constant character of the Cuculide (or 
Cuckoo family) is to have the tail composed of only ten feathers, in 
which they further resemble the Moth-hunters ; unless, indeed, the 
Ani prove to be admissible, which have but eight. It is only in the 
series of groups which compose my order Sérepitores that, through- 
out the class of birds, the tail is ever composed of less than twelve 
feathers. In the Cuckoo family, and in the neighbouring one of 
Puff-birds, the clothing feathers are single, as in the Pigeons, being 
wholly destitute of the secondary shaft, or accessory plume, which, 
in the Moth-hunters (as in the Swifts), is considerably developed. 
All have the toes disposed in pairs—that is to say, two forward and 
two behind, that which corresponds to the outer toe in the genera- 
lity of birds being reversed, as in the Parrots ; but none of them 
climb, though some have the foot expressly modified for running 
along the ground. There is a general tendency, also, to a lateral 
disposition of the two hindward toes, which is a characteristic 
structure of the Courols and Puff-birds. 
The genuine Cuckoos, or those which are included in the genus 
Cuculus as now limited, are peculiar to the eastern hemisphere, over 
which they are generally diffused, and more numerously southward 
of the equator, several species of them inhabiting New Holland.— 
Among them is a peculiar group, consisting of birds of diminutive 
size, found chiefly in South Africa, which are remarkable for the 
gorgeous brilliancy of their emerald-green plumage. The rest are 
clad in the unassuming sober livery of the species of this country. 
The British Cuckoo is very generally distributed over the greater 
part of Europe, and considerably to the northward of the British 
islands ; but it is doubtful whether it reaches far into Asia, where, 
however, there are two or three closely allied species, one of which 
(at least) utters the same cry. It passes the winter in Africa, at 
