SWIFT. 367 



crust. In this country, from the site generally chosen, the 

 structure is deeply begrimed with dust or soot, so as to pre- 

 sent, notwithstanding the neat arrangement of its materials, 

 a most uninviting aspect. Occasionally other substances are 

 added, such as shreds of cloth not unfrequently, and two 

 nests taken by Weir to Macgillivray were thickly intermixed 

 with bud-scales of the Scotch-fir, while Mr. Gould states 

 that he has found fresh petals of the buttercup adhering to 

 the inner walls. The eggs, from two to four in number, are 

 of a dead white and measure from 1*08 to '92 by from 

 •68 to '62 in. The young are ordinarily hatched about the 

 middle of June ; but they do not take flight till the end of 

 July or sometimes still later. Though zealously fed by 

 their parents, while they stay in the nest, they are but little 

 attended to afterwards, and usually the whole family leave 

 their home so soon as the young are able to sustain them- 

 selves firmly on the wing. Unless some accident happens 

 to the first eggs, the Swift produces only one set in the 

 season, but should they meet with disaster, a second seems 

 to be invariably laid, and Salmon found young in a nest so 

 late as October 1st — nearly seven weeks after all the asso- 



callecl " Swallows," belong to the Cypselidce and form the edible nests so eagerly 

 sought by Chinese epicures. These nests, one of which is here represented, are, 



when first constructed, wholly composed of mucus, which dries and looks something 

 like isinglass. Their marketable value depends on their colour and purity, for they 

 are often intermixed with fe.athers and other foreign substances. The CoUocalice, 

 of which the number of species seems to be uncertain, inhabit chiefly the islands 

 of the Indian Ocean from Mauritius eastward, as well as most of the tropical 

 islands of the Pacific as far as the Marquesas — one species occurring in the hill- 

 country of India. 



VOL. II. 3 B 



