ioo THE STORY OF THE BIRDS 



three or four white eggs. Fifth, the Diplop- 

 terinae, a very small group, containing but three 

 species ; and Sixth, the Crotophaginae, containing 

 the Anis. These are sociable birds, and curiously 

 enough when breeding several females join and 

 share the same nest. About a couple of hundred 

 species of Cuckoo are recognised. 



Our last order consists of the Passeriformes 

 or " Perching Birds." It is by far the largest of 

 the groups into which the birds of the world 

 have been divided, containing some 5500 

 species, or not quite half the number of existing 

 avine forms. The subdivision of this enormous 

 assemblage of species can scarcely be said to 

 have been satisfactorily accomplished, although 

 not a few systematists have essayed the task. 

 The present order contains the most highly 

 developed birds. Some authorities remove the 

 Broadbills (Eurylaemidae) and the Lyre Birds 

 (Menuridae) from the Passeriformes, and raise 

 each of them to the dignity of a separate 

 order ; other ornithologists refer them to dis- 

 tinct families in the order just named. The 

 separation of the Lyre Birds has the very signi- 

 ficant fact of the nestling being thickly clothed 

 in down to support it ; whilst the Broadbills 

 have certain anatomical peculiarities to warrant 



