504 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
shades which certainly harmonize with the eggs’ surroundings, a 
provision of nature most valuable for the continued existence of the 
birds as species. 
Lastly, many nests are also constructed in such a manner that they 
fit in with their surroundings, as, for instance, many of the fly- 
catchers, which build their nests in trees and cover the sides with 
lichen to conceal their real identity; or the warblers, which build in 
grass tufts, and construct their nests of various grasses deftly woven 
and placed to appear as inconspicuous as possible. 
