156 PAGAN TRIBES OF BORNEO chap. 



substance, also highly valued as a medicine by the 

 Chinese, is sometimes found as an accretion formed 

 about the end of a dart which has been broken off in 

 the flesh of 5. Hosei and has remained there for 

 some long period. 



The most important of the natural products 

 gathered by the people are the edible nests of three 

 species of swift : Collocalia fuciphaga^ whose nest is 

 white ; C. Lowii, whose nest is blackish ; and C, 

 Linchii, whose nest contains straw and moss as 

 well as gelatine. All three kinds are collected, but 

 those of the first kind are much more valuable than 

 the others. The nest, which is shaped like that of 

 our swallow, consists wholly of a tough, gelatinous, 

 translucent substance, which exudes from the bill 

 of the bird as it builds. We do not understand the 

 physiology of this process. The people generally 

 believe that the substance of the nest is dried sea- 

 foam which the birds bring from the sea on return- 

 ing from their annual migration. 



The nests are built always on the roofs and 

 walls of large caves : the white nests in low-roofed 

 caves, generally in sandstone rock ; the black in the 

 immense lofty caves formed in the limestone rocks. 

 The latter are reached by means of tall scaffoldings 

 of strong poles of bamboo, often more than a hundred 

 feet in height. The nests are swept from the rock 

 with a pole terminating in a small iron spatula, and 

 carrying near the extremity a wax candle ; falling 

 to the ground, which is floored with guano several 

 feet thick, they are gathered up in baskets. The 

 white nests are gathered three times in the year 

 at intervals of about a month, the black nests usually 

 only twice ; as many as three tons of black nests 

 are sometimes taken from one big cave in the course 

 of the annual gathering. Each cave, or, in the case 

 of large caves, each natural subdivision of it, is 

 claimed as the property of some individual, who 



