THE SWIFTS. 



35 



with the Swallows as joint members of the Order Fissirostres 

 has long been recognised as a mistake, the Swallows being 

 aberrant Passeriformes, and the Swifts being really aberrant 

 Picarice. They are, however, the most Passerine of the Pica- 

 rian birds, as they have a distinctly Passerine, or aegithogna- 

 thous, palate; in other respects they are Picarian, though in 

 many points they are aberrant members of the Order. 



In some form or other, Swifts are found nearly all over the 

 world, except in the high north and the extreme south. Where 

 no true Swifts occur, as is the case in some of the Pacific 

 Islands, their place is taken by the edible Swiftlets (Collo- 

 calia), those curious little cave-haunting birds, which make 

 the nests so highly prized by the Chinese and others for the 

 manufacture of bird's-nest soup. In Borneo these caves are 

 leased for the purposes of revenue, those which are frequented 

 by Collocalia fuciphaga, which makes the purest white nest, 

 being of more value than those inhabited by C. linchii or by 

 species which make "black" or "moss" nests, these not being 

 so useful for culinary purposes. These are, however, birds of 

 the Tropics, and in the British Islands we have but to notice 

 three species, one, Micropus opus, a regular summer visitor, 

 one, M. melba, of rare occurrence, and one, Ch&tura caudacuta, a 

 very rare visitor, of accidental occurrence only. 



THE TRUE SWIFTS. FAMILY CYPSELID^. 



The Swifts are remarkable for their very wide gape, the 

 mouth being cleft to below the level of the eyes. The wing, 

 although so powerful in flight, has less feathers in its compo- 

 sition than the bulk of Passerine Birds, for there are only ten 

 primaries, while the secondaries are less than nine in number, 

 but the quills are all very strong and pointed, so that no birds 

 on earth exceed the Cypsdida, in their power of flight. That 

 of our Common Swift is rapid enough, but this is nothing when 

 compared with the lightning-like rapidity with which some of 

 the Spine-tailed Swifts (Chcetura) traverse space. I remember 

 one Indian experience in particular, when we stopped for the 

 night at Solon, on the road to Simla, arriving there just as 

 twilight was approaching. While dinner was preparing, I 

 stood outside on the road, looking over that wonderful Hima- 

 layan scenery which I am never likely to see again, the tre- 



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