324 Mr. E. Blyth on Edible Birds' Nests. 



in 1845 {vide Journ. As. Soc. xiv. p. 210) ; and immediately 

 afterwards I circulated a printed monograph of the Indian Cyp- 

 selidcB among my naturalist friends (which I have not conve- 

 niently at hand to refer to just now). In this I gave a chemical 

 analysis of the nests by my friend Mr. J. W. Laidlay, which 

 showed the constituent proximate elements to be those of in- 

 spissated saliva. This analysis is referred to in the late Dr. 

 Horsfield's Catalogue of the Birds in the India-House Museum, 

 i. p. 103; only it is not the fact that I confirmed the researches 

 of Sir E. Home, but the reverse. He described a curious struc- 

 ture of the proventricular glands of some different and much 

 larger bird, in mistake for the CoUocalia, which does not happen 

 to possess the peculiar structure in question*; and my state- 

 ment was, that the substance of the nests was secreted by the 

 salivary glands, and not by the proventricular glands as sug- 

 gested by Home. I further pointed out, that all the Swift- 

 family use more or less of this salivary mucus in the construc- 

 tion of their nests, and that in Cypselus apus " it constitutes the 

 basis of the nest, by which is made to adhere the various light 

 substances gathered in the air by these birds, when such are 

 blown about on a windy day." {Vide he. cit.) Moreover, on 

 consideration of this composition of the edible nests, we can 

 readily understand their alleged quality of promoting digestion. 

 In the ' Revue des Deux IMondes ' for January of this year 

 (p. 218), every source but the right one of the substance of 

 these nests is amusingly cited : — " Les celebres nids d'Hiron- 

 delles nous offrent un dernier exemple de cette iugenieuse apti- 

 tude qui porte la race chinoise, sous Pinfluence d^un climat 

 special, a varier et a multiplier indefiniment les substances ali- 

 mentaires. Ces nids comestibles, dont la nature etait jusqu^a 

 ce jour demeuree incertaine, ont ete tour-a-tour attribues par 

 un grand nombre de voyageurs et de naturalistes celebres, soit 

 a une ecume de mer tenace, provenant des demeures de la 

 balcine, ramassees par ces hirondelles sur les rochersf, soit Jl 



* I have examined the proventricular glands of several specimens, both 

 of C. nidifica and of C. linchi, shot at the time that their nests were being- 

 constructed. — E. B. 



t Willuoihbv, Ifijfi. ' Oniith.' " Ex spuma maris basin scopulorum 



