T. COLUBRIS : RUBY -THROATED HUMMING-BIRD. 6l 



admits the end of one's thumb, but the walls are thick, 

 so that the entire structure is about as large as one of 

 the cups of a child's play "tea-set." The fabric is felted 

 with a mass of exquisitely soft cottony, silky, or woolly 

 substances, such as plant-down and the like, but with 

 very little coarser fibrous material, if any. Outside the 

 finish is simply perfect, being a fresco of lichens. The 

 eggs are never more than two in number ; they are pure 

 white in color, with a pink blush when fresh. The shape 

 is rather elliptical than oval, and the size scarcely half 

 an inch in the long axis by about one-third in the conju- 

 gate diameter. 



Some may have thoughtlessly believed the charac- 

 teristic sound emitted by the Humming-bird, from 

 which the name is derived, to be the voice of the bird. 

 But it is never heard when the creature is at rest, and 

 is not vocal, but mechanical, resulting from the rapid 

 vibrations of the wings, like the buzzing of bees and 

 many other insects. The sharp squeaky voice is very 

 different, and not ordinarily emitted; but is uttered 

 with great vehemence and volubility in moments of ex- 

 citement, as when the nest is threatened, when the 

 courtship grows animated, or when the battle-cry is 

 sounded to a hated rival. 



