SWIFTS. 39 



material in nest-building, as in the genus CoUocalia 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 Icteridce; 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 thine- 

 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 off- 

 spring would, during the time of incubation, be more exposed. It would be inter- 

 esting 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." 



The seven small species constituting this ffenus belonp" to the 

 Edible Swifts. . , . . 



second subfamily (Chceturince), characterised 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 (Chcetura) are called, are indeed unrivalled in 



their rapidity of flight. From the other members of the group the edible swifts 



differ by the absence of the spiny character 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; the valuable white nests, which are free from moss, 



being formed by CoUocalia fuciphaga. Writing of the habits of this species in 



Ceylon, Colonel Legge states that the breeding-season lasts from March till June, 



and that the nests form large colonies. Many of these are known, from seeing 



the birds haunt the vicinity of certain pi-ecipitous hills, but few have been visited 



and examined, on account of their general inaccessibility. The narrator then 



describes his visit to a cave on the 22nd of May, when nearly all the nests 



contained young, two being the average number. " It is noteworthy tliat the 



partially-fledged young, which were procured on this occasion for me, and which 



I kept for the night, scrambled out on the exterior of the nests, and slept in an 



upright position with the bill pointing straight up. This is evidently the normal 



mode of roosting resorted to by this species. The interior of this cave, with its 



numbers of active tenants, presented a singular appearance. The bottom was 



filled with a vast deposit of liquid guano, reaching, I was informed, to a deptli 



of thirty feet, and composed of droppings, old nests, and dead young fallen from 



above, the whole mingled into a loathsome mass with the water lodged in the 



crevice, and causing an awful stench, which would have been intolerable for a 



moment even, had not the hundreds of frightened little birds, as they screamed and 



whirred in and out the gloomy cave with a hum like a storm in a ship's rigging, 



powerfully excited my interest, and produced a long examination of the colony. 



This guano-deposit is a source of considerable profit to the estate, the hospitable 



