NESTS. AND NEST-BUILDING IN BIRDS 275 



The outer wall is smoothed and generally encrusted with fine 

 vegetable substances, such as bits of gray lichen in the case of 

 the ruby throat, or with minute leaves which were sometimes 

 green w^hen laid, with small fragments of bark, or the diminu- 

 tive seed vessels of plants. A glance at the colors of such nests 

 (table V) followed by an examination of their supports and the 

 scanty incrustation which their walls often receive, shows the hand 

 of instinct as plainly here as in other nest building operations. 

 That such birds often fresco the outer walls of their nests in 

 such a way as to protect them by making them blend with their 

 surroundings and at the same time adorn them by making 



1 



Figure 17 — Nest and egg of the anna hummingbird, attached at branching of 



twig by spiders' silk. See No. 5, table V. Small quills jjiercing this nest below 



egg, and at left. 

 Figure 18 — Nest and egg of the ruby-throated huinmingl)ird, tletached from 



twig support. See No. 1, table V, and compare figure 15: to the same scale 



as figure 17. 



them attractive to the human eye is not to be doubted, but 

 it is hardly necessary to say that the evidence does not support 

 the idea that they set about this labor with either end in view. 

 Both nests of the black chinned hummingbird referred to (Nos. 

 3 and 4, table V) were about as conspicuous as small objects 

 could well be, in consequence of the material used and through 

 lack of carrying the garnishing process to the proper stage. 



The nesting materials are bound together and to their support 

 with spiders' silk mainly, though a certain amount of saliva is 



