816 CI I .EXTRA GIGANTEA. 



fection of an all-wise Creator's handiwork, to excite wonder and admiration in the mind of the naturalist 

 and true lover of nature. That any bird can sustain an aerial course of such rapidity for 12 or 14 hours at a 

 time, without any cessation from its exertions, must of necessity excite the astonishment of the most careless 

 thinker, while to the inquiring mind it amply demonstrates what a marvel of strength and perfection of 

 structure are exhibited in this wonderful bird. A casual glance at one of these Swifts will show that it is 

 entirely formed for speed. The pointed aspect of its face and bill, with the thick lores and stiff super- 

 ciliary leathers to protect the eye from the rush of air, its broad body, gradually tapering from the rump to 

 the acute tip of the tail, give it the form of a feathered jjrojectile constructed to acquire immense velocity, which, 

 in truth, its rigid sickle-shaped wings, with their specially lengthened metacarpal bones imparting so much 

 power to the downward stroke, cannot fail to give it. It is this peculiar outward form which imparts 

 to it a so much higher power of speed than exists in other Swifts, such as the next species, for the structure 

 of the sternum is not so very much superior to that of the Alpine Swift. Dr. Sclater writes, in explanation 

 of the drawing of the sternum of this Spine-tail which is contained in the P. Z. S. 18G5, that it is broader in 

 proportion and less elongated than in Cypselus, and that the anterior point or apex of the keel is not carried 

 so far forward. Apparently these slight differences would not give the Spine-tail the superiority over the ordinary 

 Swift which it possesses were it not for its admirable external shape and greater length of metacarpus. 



This Spine-tail haunts the vicinity of rocky precipices and steep hill-sides, dividing its time between 

 careering round them and up and down adjacent valleys and sweeping over the surrounding country, especially 

 where there exist open tracts, in search of food. When hawking in a large flock its flight is not unlike that 

 of the Alpine Swift; but it is varied by vast circles and detours made with astonishing swiftness, as if merely 

 for exercise, returning in a moment to its place in the flock. It is not in this manner, however, that its 

 great powers of flight are put forth ; it is in returning at nights from its day's labours to its far-distant 

 roosting-place that these are brought out, and then its flight is as swift as the momentary rush on its quarry 

 of the Peregrine Falcon. I have experienced this on more than one occasion in the Ceylon hills, where a whiz 

 just over my head, like that of a bullet, has brought my attention to the onward course of one of these 

 birds, which the next moment had disappeared far away in the gloom of the tropical evening. Mr. Carter 

 writes, concerning a flock that he fired at, "I should not like to say how many I missed; but some idea of 

 their rate of speed may be formed when I say that in seeing one coming towards me and turning sharp round, 

 by the time T sighted it it was too far .... The two I got I killed passing over me, making great allowance 

 and firing far in front. One, although quite dead when I came up to it, had managed to clutch a stone, 

 which remained tight in its claws." Mr. Davison observed that they hawked very high in the air, betraying 

 their almosf invisible presence by a sharp clear whistle. At nights they were found, in company with other 

 .Swifts, about ponds or tanks. Concerning the roosting of this Swift, which is one of the most interesting 

 points in its economy, very little seems to be known. Its spinous tail is evidently a provision of nature to 

 afford it support against the rock to which it clings at night. It most probably, as suggested by Jerdon, 

 has some fixed roostiug-places, to which large flocks resort from immense distances, arriving no doubt at a 

 lute hour, and thus preventing the possibility of their haunt being discovered from observations of the birds 

 on their way thither. He observed that they flew towards the coast, and on one occasion witnessed an 

 enormous flock passing him on their way towards the sea some time after sunset, although there was no 

 situation on the west coast where they could have roosted; consequently the idea suggests itself that they 

 make for the sea-shore and then travel along it to their nightly rendezvous. 



Layard was informed by the natives that this species nested in rhododendron-trees, which, it is scarcely 

 necessary to remark, is an erroneous idea. It breeds, as its near ally the White-necked Spine-tail, in lofty 

 cliffs. Mr. Bligh informs me that they yearly resort to some inaccessible precipices in the Haputale ranges 

 fur the purpose of breeding, but he has been unable to hud their nests or procure their eggs. 



