NIGHT HAWKS AND WHIP-POOR-WILLS. 311 



taxonomical advances stand among the most engaging of all les- 

 sons to the philosophic ornithologist. External appearances, it 

 has taught among other things, are by no means a safe guide to 

 the orderly classification of any series of objects. Some old works 

 upon my library shelves, formerly considered " standard " and 

 "classic," contain many chapters in those premises which are 

 highly instructive on this point. One of them now open before 

 me places, according to its author, such utterly diverse bird-groups 

 as the trogans, the kingfishers, the swifts, the goatsuckers, and the 

 humming birds, all among the Passeres. Linnseus and a number 

 of his successors had no better appreciation of the truth, for the 

 scientific light shed over such fields was to them still quite dim. 

 He placed, with all confidence, the Caprimiilgi in his order Pas- 

 seres. Later, this created the usual intelligent, incredulous smile 

 of the scientific taxonomer, and in the next epoch we find in their 

 writings an " order " created to contain, among other types, the 

 swallows, the swifts, and the goatsuckers ! Then, too, think of 

 Huxley, who as late as 1867, upon osteological grounds made a 

 division Cypselomorplice, to which he restricted the swifts, the 

 humming birds, and the goatsuckers. A decision of that kind 

 coming from such an influential quarter has carried with it the 

 weight of conviction to the minds of our most recent ornithologi- 

 cal writers and systematists. And we find Elliott Coues, in his 

 last revised edition (1890) of his Key to North American Birds, 

 still adhering to the old order Picaricp., in the first group of which, 

 the Cypseliformes, he places the swifts {CypselidcB), the goatsuck- 

 ers {Caprimulgidod), and the humming birds {Trocliilidm). But a 

 far more unnatural grouping is seen in the Manual of North 

 American Birds, by Mr. Robert Ridgway, where an order Macro- 

 cliires is retained to contain the goatsuckers, the swifts, and the 

 humming birds, and in this he is followed by the check list of the 

 American Ornithologists' Union. What special kinship the sys- 

 tematist sees between a humming bird and a whip-poor-will, the 

 morphologist in these days certainly fails to appreciate. Ana- 

 tomically the writer has examined in great detail several species 

 of difl^erent genera of both humming birds and goatsuckers, as he 

 also has many swifts and swallows, and is of the opinion that the 

 Caprimidgi are most nearly related to the owls, while the swifts 

 are but profoundly modified swallows. To thoroughly appreciate 

 such affinities it is necessary that we should have before us the 

 so-called " outliers " of the various groups just named. 



Representatives of the suborder of birds, United States species 

 of which we are here considering, are found in many parts of the 

 world, though they appear to be entirely absent from the avif aunse 

 of Polynesia and New Zealand. In South America, in Asia, in 

 Africa, and in Australia we meet with goatsuckers of the most 



