200 Wonders of the Bird World 



in Ceylon, to a depth of thirty feet. Mr. Harry Pryer 

 found that in one of the great caves of Northern Borneo 

 a pole thrust into the guano to a distance of eighteen feet 

 did not reach the bottom, and there was over the floor an 

 average accumulation varying from five to fifteen feet, so 



Nests of Edible Swiftlets, from Bornean specimens in the Natural History 

 Museum, presented by Mr. Charles Hose. 



that it is evident that the caves inhabited by the Swiftlets 

 must have been tenanted by these birds for a very long 

 period. The glands which supply the secretion from 

 which the nest is principally composed, were found by the 

 late Dr. Bernstein to be situated, like two pads, at the side 

 of the tongue. These glands only become enlarged at the 



