THE ESCULENT SWALLOW. 319 



seldom wander to any great distance as long as they remain in the 

 country. 



In general, the Swift loves to build its nest in a hole under a roof, 

 whether slated, tiled, or thatched, preferring, however, the warm, thick 

 straw-thatch to the tile or slate. Sometimes it makes a hole in the 

 thatch, through which it gains access to the nest, but in most instances 

 it makes use of some already-existing crevice for that purpose. In all 

 cases the nest is placed above the entrance, and may generally be found 

 about eighteen inches or two feet from the orifice. Even by the touch 

 the eggs of the Swift may be discerned from those of any other bird, 

 as their length is singularly disproportionate to their width. 



The sound which these birds utter is of the most piercing description, 

 and can be heard at a very great distance, thus betraying them when 

 they are hawking after the high-flying insects at such an altitude that 

 their forms are hardly perceptible to the unassisted eye. 



The nest is a very firmly made but yet rude and inartificial structure. 

 The materials of which it is made are generally straw, hay, and feathers, 

 pieces of rag, or any soft and warm substance which the bird may find 

 in its rambles, and when woven into a kind of nest are firmly cemented 

 together with a kind of glutinous substance secreted by certain glands. 

 In Norway and Sweden the Swift builds in hollow trees. The eggs are 

 from two to five in number, not often, however, exceeding three, and in 

 color they are pure white. In this country the Swift pays but a very 

 short visit, as the bird evidently requires a v§ry high temperature, and 

 is forced to depart as soon as the weather becomes chilly. Generally 

 the Swifts leave England by the end of August, but there are often in- 

 stances where a solitary bird has delayed its voyages for some good 

 reason. 



Among the many " travellers' tales " which called forth such repudi- 

 ation and ridicule from the sceptical readers of the earlier voyagers, the 

 accounts of the Chinese cuisine were held to be amongst the most ex- 

 travagant. 



That civilized beings should condescend to eat dogs and rats specially 

 fattened for the table was an idea from which their own better sense re- 

 volted ; that the same nation should reckon sharks' fins and sea-slugs 

 among their delicacies was clearly an invention of the writer ; but that 

 the Chinese should make soup out of birds' nests was an absurdity so 

 self-evident that it destroyed all possibility of faith in the writers' pre- 

 vious assertions. 



The birds that make these remarkable nests belong to several species, 

 four of which have been acknowledged. These are the Esculent 

 Swallow, the Linchi {Collocalia fuciphaga), the White-backed Swal- 

 low [Collocalia troglodytes), and the Gray-backed Swallow {Colloccdia 

 Francica). 



