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FRANCIS H. HERRICK 



all reptiles at the present time, and many have made a success 

 though sticking to the rut of ages; in many too such as parrots, 

 woodpeckers, and pigeons, the eggs have grown whiter, if any- 

 thing, despite all change which may have ensued in the family 

 or species; some too like the magpies have changed their nesting 

 habit long after they acquired richly pigmented eggs. All ques- 

 tions of comfort to sitter or young, or even protection from the 

 elements, with the exceptions noted, in dealing with the class, 

 must be considered as of secondary importance to concealment 



Figure 1 — Open nest with pure white eggs of mourning dove, Zenaidura macroura. 

 remove(i from support ; shallow saucer or platform of loose twigs and rootlets. 

 Simple form of statant type. 



and to protection by other means ; we know that they are often 

 discounted, at whatever cost. 



To recapitulate: any theory of nests which lays the main 

 emphasis upon the color of the adult or young, or upon these 

 factors in relation to nesting habit, must be unsatisfactory 

 because it cannot be generally applied. Any theory of organic 

 evolution must account for all the characters of such animals 

 or for none. The theory of selection gives as good an account 

 of the nests of birds as it gives of their structure, colors, or 

 instincts, but no better. In dealing with the nests there are 



