THE BIRDS OF AUSTRALIA. 
favourable. Wlien, however, we began to explore a darksome cavern well 
hidden in the jungle, the excited fluttering of invisible birds revealed a hitherto 
well-kept secret. When our eyes became accustomed to the dimness we saw that 
the roof of the cave (which is fairly smooth and regular, with an inclination of 
about 30°) was studded with nests. I counted fifty-three, placed irregularly 
about the middle of the cave ; none on the walls. Some nests were apparently 
not quite finished ; twenty contained a single white egg each ; none contained 
young. All were adherent to the roof by a semi-transparent white substance 
resembling isinglass, with which also the grass, tendrils, and bark composing 
the nests were consohdated. The vegetable material of which the first nest 
found (17th September) was made was quite green and the gluten moist and 
sticky. Those of to-day were hard-glued into sohdity. After the first fright 
the birds became very quiet and confiding. A young one flew iato my hand, 
and I detained it for a while without a struggle. Another tried to snoodle 
into the shirt-pocket of the black boy who accompanied me. Several brushed 
against our faces. The weather was quite cloudy, and what with the screen 
of fohage and the prevailing gloom of the cavern we could not always distmguish 
the nests. When the sun shone brightly they were all readily discernible, 
those with the single white egg looking very quaint. As they flitted in and 
out of the cavern the birds were as noiseless as butterflies, save when they 
wheeled to avoid each other. Those which were brooding, as they flitted 
over their nests and clung to the edges, uttered a peculiar note, hard to render 
into words. To my ears it seemed a blending of cheeping, clicking and chatter- 
ing, yet metallic, and not very unlike the quick winding up of a clock. One 
bird flew to her nest a foot or so from my face, and clung to it. To test its 
timidity or otherwise I approached my face to within 2 inches of her, but she 
continued to scrutinise me at even these close quarters with charming assurance. 
Then I gently placed my hand over her. She struggled gently for a few seconds 
and then remained passive, her bright eyes glinting in the gloom. She was 
a dusky little creature, the primaries, the back of the head, neck, shoulders 
and tail being black, but when the wings are extended for flight the white down 
at the base of the tail is very conspicuous. After a few minutes I put her 
back in the nest and she clung to it, having no fear of me. I noticed that 
the beak was very small, the gape very large ; the legs short and the toes slender. 
We remained in the cave for about hah an hour, throughout which time the 
birds came and went, indifferent to our presence. In the interests of science, 
but to the violence of my own sentiments, I secured two specimens of the nests 
and four eggs for you. One egg was quite fresh ; one had just germmated ; 
the incubation of the third was well advanced ; the fourth contained a live 
chick. It is interesting to note that, while many young birds were fluttering 
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