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THE POPULAR SCIENCE MONTHLY. 



varied kinds, both in the matter of form and plumage. One of the 

 most evident types exemplifying the kinship between the Capri- 

 mulgi and the owls is the extraordinary species found in the caves 

 of Caripe in South America and in Trinidad. This is the well- 

 known " oil bird," the Steatornis caripensis of science, and also 

 called the guacharo by the natives, who enter every season the 

 caves where it breeds to collect the young. This is done to obtain 

 the grease by trying out their fat-laden bodies, and thus the spe- 

 cies has a certain economical importance. In its structure Stea- 

 tornis is much like some owls, and its two to four white eggs, laid 



Fig. 2. The Whip-poor-will [A. voci/erus), S Diiiwn by the author and much reduced. 



in a nest built by the bird of clay, closely resemble the eggs of 

 certain birds of that group. Likewise it is nocturnal in habit, and 

 markedly differs from the average goatsucker inasmuch as it feeds 

 upon fruit and certain oily nuts. Structurally it has been exam- 

 ined with some care by the British anatomist Garrod, who fully 

 appreciated its relation to the owls. Well it may be said that 

 most owls have long legs which they can use to full advantage, 

 which our night hawks and whip-poor-wills do not possess, those 

 members being so short in them that they can only shuffle over 

 the ground with difficulty. Yes, but there is also a Central and 

 South American species of goatsucker, with legs so long that it 

 can run upon terra firma with all the swiftness and ease of one of 



