128 



Fig. 59. Nestling Mourning Doves (Zenaiditra macroura). From U. S. Dept. Agriculture 



Year-Book, IQOO. 



Questions on the figure. — Is there anything suggestive of protective markings? 

 What are the nesting habits of the dove? What character of nest is constructed? 



Fig. 6o 



A sea-horse, — Phyllopteryx eques. From Eckstein. 



Questions on the figure. — Compare this figure of sea-horse with figures of 

 other species and note the chief difference between them and the typical fishes in 

 external characteristics. What about the figure suggests protective resemblance? 

 At what point does the tail of the fish end? 



