A Theory of Birds' Nests 79 



VI. Hombills (Bucerotidae). These large birds have enormous 

 coloured bills, which are generally quite as well coloured 

 and conspicuous in the females. Their nests are always 

 in hollow trees, where the female is entirely concealed. 



VII. Barbets (Capitonidte). These birds are all very gaily 

 coloured, and, what is remarkable, the most brilliant patches 

 of colour are disposed about the head and neck, and are 

 very conspicuous. The sexes are exactly alike, and the 

 nest is in a hole of a tree. 



VIII. Toucans (Rhamphastidae). These fine birds are coloured 

 in the most conspicuous parts of their body, especially on 

 the large bill, and on the upper and lower tail coverts, which 

 are crimson white or yellow. The sexes are exactly alike, 

 and they build always in a hollow tree. 



IX. Plantain-eaters (Musophagidas). Here again the head and 

 bill are most brilliantly coloured in both sexes, and the nest 

 is in a hole of a tree. 



X. Ground cuckoos (Centropus). These birds are often of 



conspicuous colours, and are alike in both sexes. They 

 build a domed nest. 



XI. Woodpeckers (Picidte). In this family the females often 

 differ from the males, in having a yellow or white, instead 

 of a crimson crest, but are almost as conspicuous. They 

 all nest in holes in trees. 



XII. Parrots (Psittaci). In this great family, adorned with the 

 most brilliant and varied colours, the rule is, that the 

 sexes are precisely alike, and this is the case in the most 

 gorgeous families, the lories, the cockatoos, and the 

 macaws ; but in some there is a sexual difference of colour 

 to a slight extent. All build in holes, mostly in trees, but 

 sometimes in the ground, or in white ants' nests. In the 

 single case in which the nest is exposed, that of Pezoporus 

 formosus, the bird has lost the gay colouring of its allies, 

 and is clothed in sombre and completely protective tints 

 of dusky green and black. 



XIII. Gapers (Eurj'lsemidse). In these beautiful Eastern birds, 

 somewhat allied to the American chatterers, the sexes are 

 exactly alike, and are adorned with the most gay and con- 

 spicuous markings. The nest is a woven structure, covered 

 over, and suspended from the extremities of branches over 

 water. 



