the Habits o/Micropus melanolencus. 153 



insect prey in tlie uj)per air^ but Avhen cloudy or rainy we 

 finrl them skimming the ground in their pursuit. When on 

 the ground, the shortness and weakness of their legs, added 

 to their length of wing, incapacitates them from again rising 

 in the air ; hence I have several times seen the European 

 species, C. murarius, picked up in the streets of Geneva, 

 Switzerland, having fallen there during a quarrel with its 

 fellows. When they wish to take rest during the day, which 

 is rare, they always alight on some elevated point, whence 

 they can throw themselves into the air and take to wing. 



"Though numbers were flying about the rocks near 

 Tucson, I heard them utter no note. Sociable among them- 

 selves, gathering in large flocks, they never mingle with their 

 nearly related brethren the Swallows. They generally con- 

 struct their nests in the crevices of rocks or the holes in old 

 buildings, many species having secretory glands, exuding a 

 glutinous substance with which to fasten them firmly. The 

 eggs, from 4 to G in number, are pure white and of an elon- 

 gated form^' *. 



Some of these observations I can confirm, but up to the 

 present time I have never been so fortunate as to see one of 

 these Swifts alight in any locality. On one occasion I saw 

 a pair of them commence to quarrel high up in the air, and 

 continue the closely contested claw-and-wing conflict until 

 they reached the ground, where the dust they raised pre- 

 vented me from clearly seeing their movements ; but in a 

 second they were both in the air again, and oft' like two darts, 

 in different directions. 



Very rarely have I seen them circle about, as described 

 by Dr. Heermann, but, on the contrary, at all times during 

 ordinary flight, either high up or low down, there is, at 

 closely following intervals, rapid movements of the wings. 

 Sometimes one will shoot down from an enormous height 



* A. L. Heermann, M.D., in * Reports of Explor. and Surveys to 

 ascertain the most practicable and economical route for a Eailroad from 

 tlie Mississippi River to the Pacific Ocean,' 1853-56, vol. x. (Washington, 

 1859, p. 10) of report on the 13irds. 



