PANYPTILA SAXATILIS, WHITE-TIIROATED SWIFT. 265 



are batcbed downy. This is a singular circumstance, in which the 

 Caprimukjidcc resemble the lower orders of birds, and not the higher 

 groups witli which they are associated. The chicks are not, however, 

 hatched entirely clothed; for the first two or three days they are only 

 densely llocculent on the under parts, the upper being but sparsely 

 downy ; soon, however, they are uniformly covered with down, varie- 

 gated above^ plain below. The design of this provision is evidently 

 protection from the danip ground on which the young rest. In the 

 several instances of nesting I have found, there was nothing whatever 

 between the birds and the earth ; but occasionally, it is said, a few 

 leaves or straws lie underneath them. A favorite nesting place, in the 

 West, is the little mounds of loose soil thrown up by the gophers, either 

 in open fields or by the edge of woods. Tlie birds are also said to lay 

 on the mould of stumps and logs, but I have never found eggs in such 

 situations. One of the two eggs may be hatched sooner than the other; 

 in one instance I found an interval ot three days to elapse, during which 

 I frequently visited a nesting place. The female, on each occasion, 

 remained near her charge until nearly trodden upon, and then fluttered 

 off, making believe she was crippled, as perfectly as I ever saw the pious 

 fraud performed in my life. Not having much, if any, legs to be lame 

 in, she simulated a broken wing, fluttering and pitching about in the 

 grass, at no time more than a lew feet off. The statement that the bird 

 will remove her young, if disturbed, is true. The bird I am alluding to 

 carried them to another hillock, after my second visit, but only a couple 

 of yards away. The male, on each occasion, came dashing overhead, 

 sometimes darting close down, but did not join the mother in her at- 

 tem[)ts to decoy me away. 



I have found the Night-hawk nesting in the Carolinas and Dakota, as 

 it apparently does in most of its United States range. The eggs are 

 nearly elliptical, blunt at the smaller end, where nearly as large and 

 rounded as at the other. They measure about 1.30 by 0.90, but vary a 

 good deal. The coloration is blended, intricate, and difidcult of descrip- 

 tion. The ground-color is a pale stone-gray, sometimes grayish-white, 

 obscurely mottled all over with |>ale purplish gray or neutral shell- 

 markings, over which is laid a marbling or scrat(fhy fret-work of dark 

 olive-gray. Tiie tone of the markings — rather, the number and intensity 

 of the markings, resulting in the general tone of coloration — is ex- 

 tremely variable, some very pale, scarcely clouded, eggs being met with. 



Family CYPSELID^ : Swifts. 



PANYPTILA SAXATILIS, (Woodh.) Coues. 

 White-throated or Rock Swift. 



Jcautln/liH xaxatilis, Woonn.. Sitgr. Rep. 1853, 64.— Cass., 111. i, 1855, 252. 



ranjiptUa mixafilis, CouES, Key, 1872, 182. 



Cypwhis mvhivolciicm, Bd., Pr. Pbila. Acad. 1H.')4, 118.— Cass., 111. i, 18.55, 248. 



rumjpUla mduiioUmca, Bi)., B. N. A. 1858, 141.— Kkxn., P. R. R. Rep. x, 1859, pt. iv, 23.— 

 HiCKHM., ibid. pt. V, 10; pt. vi, 35, pi. 18, lower fig.— ScL. &- Salv., Ibis, 1859, 

 125 (biography).— Coop., Pr. Cal. Acad. 18G1, 122 (Cajon Pass, Soutberu Cali- 

 forniii).— Cour.s, Phila. Acad. 1866, 57.— ScL., P. Z. S. 18:55, 607.— Coop., B. 

 Cal. i, 1870, 347.— Ai.uoN, Bull. M. C. Z. iii, 1872, 151, 180 (Colorado).— Aiken, 

 Pr. Bost. Soc. XV, 1872, 206.— B. B. &. R., N. A. B. ii, 1874, 424, pi. 45, f. 5. 



ffafe.— Southern Rocky Mountain region to the Pacific. North to headwaters of the 

 Platte at least. South to Guatemala. 

 Not noticed by (he Expeditions. 



Respecting the Acauthylis saxatiUs of Dr. Woodhouse, I remarked on 



