114 



ESCULENT SWALLOW. 



terruption: the birds that build these nests are 

 small grey Swallows, with bellies of a dirty white. 

 They were flying about in considerable numbers, 

 but were so small, and their flight was so quick, 

 that they escaped the shot fired at them. The 

 same sort of nests are said to be also found in 

 deep caverns at the foot of the highest mountains 

 in the middle of Java, at a distance from the sea ; 

 from which source it is thought that the birds 

 derive no materials either for their food or the 

 construction of their nests, as it does not appear 

 probable they should fly in search of either over 

 the intermediate mountains, which are very high, 

 or against the boisterous winds prevailing there- 

 about : they feed on insects, which they find hover- 

 ing over stagnated pools between the mountains, 

 and for the catching of which their wide opening 

 beaks are peculiarly adapted. They prepare their 

 nests from the best remnants of their food. Their 

 greatest enemy is the kite, who often intercepts 

 them in their passage to and from the caverns, 

 which are generally surrounded with rocks of grey 

 limestone or white marble. The nests are placed 

 in horizontal rows, at different depths, from fifty 

 to five hundred feet : the colour and value of the 

 nests depend on the quantity and quality of the 

 insects caught, and, perhaps, also on the situation 

 where they are built : their value is chiefly ascer- 

 tained by the uniform fineness and delicacy of 

 their texture; those that are white and transpa- 

 rent being most esteemed, and fetching often their 

 weight of silver in China, 



