248 EDIBLE SWALLOW NESTS. 



with the profit they make by selling them to the Chinese, who 

 are the chief purchasers. 



The two bird-mountains above alluded to, are insulated 

 rocks, hollow within, and pierced with a great number of open- 

 ings. Many of these openings are so wide, that a person can 

 enter them with ease ; others are attended with more difficulty, 

 and some are too small to admit of intrusion ; in these, thcre- 



Edible Swallows and Nests. 



fore, the poor little birds are alone safe from robbery. To the 

 walls of these caverns the birds affix their small nests in regular 

 rows, and so close that for the most part they adhere together. 

 They construct them at different heights, from fifty to sixty 

 feet, sometimes higher, sometimes lower, according as they find 

 room \ and no hole or convenient place, if dry and clean, is 

 left unoccupied j but if the walls be in the least wet or moist, 

 they immediately desert them. At daybreak, these birds fly 



