164 BIRDS' NESTS 



externally with a mosaic of lichen, which causes the 

 nest to appear nothing but a knob or excrescence 

 upon the similarly lichen-garnished limb or trunk of 

 a tree. A third and similarly constructed nest 

 belongs to Costa's Humming-bird {Calypte costce). 

 This is also attached or saddled to the upper sur- 

 face of a branch, and is composed externally of 

 lichens and flakes of bark bound together by spiders' 

 webs and lined with feathers. A fourth of the same 

 general type is made by the Calliope Humming-bird 

 (Stellula calliope), and usually fastened to the upper 

 side of some dead twig. As an instance of the in- 

 telligence and adaptability of Humming-birds we may 

 mention that a nest of this species, discovered by 

 Dr Merrill in Oregon, was built upon a dead, flattened 

 cone of Pinus contorta. It was fashioned externally 

 of thin strips of grey bark, cemented together with 

 spiders' webs ; lined with the same kind of bark, with 

 a few added tufts of cottony blossom, and so closely 

 matched in colour the cone that supported it, that it 

 was discovered with difficulty. A somewhat different 

 type of nest is slung in the fork of some twig. A 

 capital example of this type is presented by the nest 

 of the Circe Humming-bird {lache latirostris)', another 

 built in precisely similar situations is that of Xantus's 

 Humming-bird {Basilinna xantusi). This latter is 

 securely interwoven between two forks or prongs of 

 a twig resting between them. It is composed chiefly 

 of raw cotton, thickly coated outside with spiders' 



