376 BRITISH BIRDS. 



Family CUCULIDiE, or CUCKOOS. 



The Cuckoos are a large group of birds presenting great diversity of 

 general appearancej but fairly well defined from their alUes^ the nearest of 

 which are probably the Musophagidse^ or Plantain-eaters^ of the Ethiopian 

 Region. Sclater associates them with the Woodpeckers^ Kingfishers, 

 Swifts, and other Picarian families j Gadow regards them as a connecting- 

 link between the Pheasants and the Picarian birds j whilst Forbes placed 

 them amongst the Pheasants, Bustards, and Rails, on account of the 

 presence in the latter groups of birds of the ambiens muscle. Like the 

 Passerine birds, they have only one notch on each side of the posterior 

 margin of the sternum ; but their pterylosis is said not to be Passerine in 

 character, though very variable. Huxley associates them with the King- 

 fishers, Hoopoes, Bee-eaters, and Rollers. Gadow says that in their 

 digestive organs they most resemble the Bee-eaters, Rollers, and Goat- 

 suckers. 



The true Cuckoos moult twice in the year, in spring and autumn ; but 

 whether this be the case with the more distantly allied genera I am unable 

 to say. 



The Cuckoos may be divided into numerous subfamilies presenting great 

 variety of appearance, and scarcely possessing any external character in 

 common except that of having two toes in front and two behind. In the 

 true Cuckoos, or Cuculinee, most of the species show great superficial 

 resemblance to a Sparrow-Hawk, especially in their long and somewhat 

 rounded wing, which contains ten primaries, and long graduated tail, 

 composed of ten or twelve feathers. The shape of the bill somewhat 

 resembles that of the Thrushes. 



There are about 180 species of Cuckoos, belonging to various genera, 

 which are distributed all over the world, except in the Arctic regions. 

 Two species only are found in Europe, one of which is a regular summer 

 visitor to our islands, and the other is said to have visited them once. 

 Two American species are also said to have accidentally strayed as far as 

 Ireland. 



Genus CUCULUS. 



The genus Cuculus was recognized by Linnseus in the twelfth edition of 

 his ' Systema Naturae' (i. p. 168), published in 1766. C. canorus (the 

 Cuculus cuculus of Brisson) is the type. 



