172 Darwin and Romanes dealt with. 



others, which, having been much persecuted by tree- 

 chmbing snakes taking their eggs from an open nest 

 on a tree as with the baya bird, fell to building a 

 nest, hung by a kind of long fibres from an aloe leaf 

 from a bough overhanging a stream, and within a 

 foot of it, and now so constructed the nest that it had 

 to be entered from below ; the nest really being at 

 the far-end of a short passage, and so balanced that 

 the eggs and young would only weigh it enough to 

 make it hang really even — that is, before they come, 

 the opening or mouth of the nest drooping at a kind 

 of slant, and when they do come it hangs even or 

 almost even. 



We have nests in so far of the same general char- 

 acter in the case of the Sitarya ocularis of Bathurst, of 

 which there is a fine specimen presented to the South 

 Kensington Museum by Dr. Rendall, and yet another, 

 the nest of the weaver-bird of Uganda ; or another 

 still, in the very variable suspended bottle-nest of the 

 grey warbler of New Zealand, as figured in Sir W. 

 L. BuUer's handbook. 



A further and most striking instance is that of the 

 Leipoa ocellata of Australia, which systematically 

 places its eggs to be hatched by heat of fermentation 

 in the centre of a vast mound of leaves, and mould, 

 and dust, yards square — the young ones forcing their 

 way out of the mound when hatched, without the 

 least help from the parents. Mr. John Gould has 

 given full descriptions of this bird and its habits in 

 Introduction to Birds of Australia, Ixxiii, where 

 drawings of the mound and nest are also presented. 

 There is here the same correspondence between the 

 nest-building of the parents and the instinct given to 



