i8o2 THE PICARIAN BIRDS 



in their pursuit. When on the ground, the shortness and weakness of their legs, 

 added to the length of their wing, incapacitates them from again rising in the air; 

 hence I have several times seen the European species ( M. aptis} 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 themselves, gathering in large flocks, they never 

 mingle with their nearly related brethren, the swallows. They generally construct 

 their nests in the crevices of rocks or the holes in old buildings; many species have 

 secretory glands, exuding a glutinous substance with which to fasten them firmly. 

 The eggs, from four to six in number, are pure white, and of an elongated form." 

 The two species constituting this genus, although resembling the 



^ e pied swift in the feathering of the toes, differ in the form of the tail, 

 Switts 



the outer feathers of which are pointed. The Cayenne species 



(Panyptila cayennensis) ranges through Colombia, Guiana, and Amazonia, while 

 Salvin's swift (/*. sancti-hieromini) inhabits Gautemala. The latter is an unusually 

 beautiful bird for such a dull-colored family, its general hue being silky black, with 

 a narrow white collar round the hinder part of the neck, while the wings and tail 

 also show a good deal of white at the bases of the feathers. Writing of a nest 

 devoid of eggs, which he found in Gautemala, Mr. Salvin observes that "in this 

 nest we see the saliva of the bird used as an adhesive material in nest building, as 

 in the genus Collocalia of the Old World, but differently applied. At first sight the 

 saliva appears to have been used merely to secure the foundation of the nest (if 

 the term may be used inversely) to the overhanging projection of rock upon which 

 the rest of the structure is woven, as in the nests of the Icteridtz; but, upon closer 

 examination, it will be seen that the saliva has been applied to secure every one of 

 the seeds used in the construction of the nest, and in no other way could so firm 

 and durable a structure be obtained. Another curious feature will be noticed in 

 this nest, which is the false entrance at the side. I remember to have seen a similar 

 thing in other nests. They appear to be placed there to deceive some enemy, such 

 as a snake or lizard, to the attacks of which the parent bird and its offspring would, 

 during the time of incubation, be more exposed. It would be interesting to know 

 how the materials for the nest were gathered, whether from the plant itself, or 

 caught in the air by the bird as the seeds were carried by the wind." 

 Edible Swifts ^ e seven small species constituting this genus belong to the second 

 subfamily ( Chceturina:} , characterized by the elongated wings, and the 

 generally spiny tail, in which the shafts of the feathers are prolonged beyond the 

 barbs so as to resemble needles. The needle-tailed swifts, as the members of 

 the typical genus {Ch&tura) are called, are indeed unrivaled in their rapidity of 

 flight. From the other members of the group the edible swifts differ by the 

 absence of the spiny characteristic in the tail; their chief claim to our interest being 

 their peculiar nests, which form an article of food in the East. Formed chiefly from 

 the birds' saliva, these nests are firmly attached to the walls of caverns. Mr. C. 

 Hose has discovered that the different species of the genus build distinctive nests; 



