BUSH HENS. 325 



are of comparatively rare occurrence. I never found any calcareous 

 pebble in their gizzards, and was often at a loss to explain how the 

 bird was able to ascertain for itself the different desrree of hardness 

 between the two pebbles, when the quartz was of the dull white 



variety I learn from a recent work on New Guinea by the 



missionaries, Messrs. Chalmers and Gill, that inside the gizzard of 

 each Goura pigeon there is a good-sized pebble much prized by the 

 natives as a charm against spear-thrusts and club blows.^ The 

 Goura pigeon resembles the Nicobar pigeon in habits ; and I think 

 it probable that its gizzard will be found to present a similar 

 structure and mechanism for ciacking nuts and hard seeds. The 

 common fruit pigeons {Carpophaga) of the Solomon Islands, living 

 as they do on soft fleshy fruits, and rejecting the hard seeds and 

 kernels, have no peculiar structure of the gizzard, the walls of which 

 are comparatively thin, and are thrown into permanent rugae some- 

 what warty on the surface. 



One of the most familiar birds in these islands is the "bush-hen," 

 which belongs to the family of the mound-builders {Megapodiidce). 

 They biiry their eggs in the sand at a depth of between three and 

 four feet. On one occasion in the island of Faro, Lieutenant Hemino- 

 and his party found eight eggs, in different stages of hatching, thus 

 buried : they were scattered about in the sand ; and according to 

 the account of the natives only one &gg was laid by each bird. The 

 eCTOfs are sometimes found on the surface of the sand. The youno; 

 birds are able to fly short distances soon after they are hatched. 

 One that was brought on board astonished us all by flying some 

 thirty or forty yards from the ship and then returning to the rigging. 



The account recently published by Mr. H. Pryer of his visit to 

 the birds' nest caves of Borneo ^ has opened up the discussion as to 

 tlie nature of the substance of which the edible bird's nest is com- 

 posed. Many and varied have been the surmises as to the source of 

 this material; but nearly all of them have been based on mere 

 speculation, and have been relegated to the limbo of sea-tales 

 Amongst the earlier explanations, I may allude to those which have 

 been given by early writers. The swif tlets {Collocalia), which build 

 their nests in this extraordinary fashion, were considered to gather 

 a gelatinous material from the ocean-foam, or from the bodies of 

 holothurians, or from the skin of the sun-flsh. The Chinese flsher- 



^ " Work and Adventure in Now Guinea " (p. 317) : London, 1SS5. 

 -Proceedings of the Zoological Society for 1884 : p. .532. 



