OPEN NESTS 203 



family of South American birds, the Wood - hewers 

 (Dendrocolaptid£e). In no other family do we find a 

 greater diversity of architecture, the most striking 

 examples, however, belonging to such types that will 

 require consideration elsewhere. The nests, however, 

 of the Ant Thrushes (Formicariidas) are generally of 

 an open type. This group is also peculiar to the same 

 region. They place their nests in trees and bushes. 

 These nests are shallow saucer rather than cup- 

 shaped in form, and composed of grasses, fibres, 

 moss, roots, wool, and hair. Lastly, we may allude to 

 the family of Wren-like birds (Pteroptochidas), chiefly 

 confined to the temperate regions of South America, 

 in which the architecture presents not a little diversity, 

 although the group is such a small one, numbering no 

 more than about a score of species. Some of these 

 birds nest in burrows, others make domed nests of 

 grass, whilst certain species construct an open nest 

 composed chiefly of sticks. 



The length of the present chapter bears significant 

 testimony to the prevalence of the open or cup-shaped 

 style of architecture amongst birds. If the number 

 and variety of species building these open nests can 

 be taken as any indication, we are, I think, fairly 

 justified in coming to the conclusion that such a type 

 is the most natural style of architecture in the entire 

 avine class; and also that all divergence from that 

 specially normal type has been caused by a vast 

 variety of exceptional circumstances and conditions 



