OPEN NESTS 169 



saucer 1'75 inches in diameter and about 0-6 in 

 depth internally. The nest is entirely composed of 

 thin flakes of bark, cemented together by the birds' 

 saliva, and is about an eighth of an inch in thickness. 

 The female, in incubating the solitary egg, is said to 

 sit transversely across the thin branch. The nest of 

 the Colies (Coliidse) require passing notice. 



We have already dealt with the nests of the Parrots, 

 the Plantain-eaters and Cuckoos. Some, however, 

 belonging to the latter birds, as well as a few of the 

 Parrots, are sufficiently elaborate to be included in 

 the following chapter devoted to the consideration of 

 domed and roofed nests (conf, p. 212). We now reach 

 that vast assemblage of birds scientifically termed 

 Passeriformes. This, by far the largest order of 

 existing birds, numbering upwards of five thousand 

 five hundred species, contains not only the most 

 highly specialised, but the most widely distributed 

 avine forms. They are found in more or less abund- 

 ance over all the earth, and are consequently exposed 

 to an infinite variety of conditions, which fact is re- 

 flected in their architecture. As we stated when 

 briefly reviewing the reproduction methods of this 

 group in our recently-issued introductory volume to 

 ornithology,! gg may we here repeat. The variety in 

 the nests of the Passeres can only be described as 

 amazing, and must be taken as an indication of the 

 high degree of specialisation to which the order has 

 The Story of the Birds, p. 250. 



