186 



ORNITHOLOGY. 



" On reaching the cave, we found that it was one which was for- 

 merly supposed to be the residence of one of the native gods, ' Moso.' 

 Our Samoan companions pointed out the place, but declined entering, 

 and we found that a wall had been built across the entrance, leaving 

 but a narrow aperture through which the passage was given into utter 

 darkness, but being prepared with matches, candles, and a lantern, we 

 soon were on our way through a regularly formed volcanic tunnel, or 

 passage, which was once an outlet by which lava in its molten state 

 found its way from the mountains to the sea. 



" A sound like the rattling of small hard pebbles was heard, and soon 

 traced to numerous swallows, which had been disturbed by our lights, 

 and many others were discovered sitting quietly on their nests placed 

 on slight ridges of the lava. The nests were composed of moss, held 

 together with glue incorporated with the moss in large quantities; like 

 the walls of the cave, they were dripping with moisture ; each con- 

 tained but one egg or young bird, and incubation did not appear to 

 be confined to any particular season. Some were just building, while 

 the young of others had quitted the nest, and were just beginning to 

 fly. Old nests were repaired Avith new moss, which made it appear 

 that they used the same more than once. Some of the old birds were 

 so unsuspicious that they allowed us to lift them off their egg with 

 our hands, and they immediately returned when we were satisfied. 

 The nests are nearly round, three inches in diameter, and about one 

 and a half inches high. The eggs are pure white, one end nearly as 

 small as the other, three-quarters of an inch long, and half an inch in 

 diameter. 



" Notwithstanding that these swallows are known to fly through 

 long subterranean passages in total darkness, they may daily be seen 

 abroad even in clear sunlight, collecting food for themselves and their 

 young, so that it is probable there will be found on careful examina- 

 tion, some anatomical structure which enables them to alter the form 

 of their eyes, and to see in the dark and in the light, 



" The two sexes are alike in plumage, which the young also wear 

 from the first moult. We had frequent opportunities of seeing this 

 species at Upolu, and at Tutuila, of the Samoan Islands, and at several 

 of the Feejees." 



This bird is represented in our plate of the natural size. 



