130 BIRDS' NESTS 



in the organisation of these curious birds, which 

 necessitates a considerable period between the pro- 

 duction of each successive egg, an interval of three 

 months being required to produce eight eggs. That 

 the birds do produce their eggs at long intervals 

 (possibly a fortnight between each) seems to be 

 unquestionable, but this may be caused by the peculi- 

 arities of their nesting methods and not vice versa. 

 Reasoning by analogy Dr Wallace's explanation, 

 ingenious as it certainly is, does not seem to us a 

 satisfactory one. The Mound Birds are considered 

 by anatomists to be morphologically the lowest in 

 the order Galliformes ; and possibly their abnormal 

 methods of reproduction may represent an equally 

 archaic means of incubation, inherited from some 

 early avine ancestor, living in those remote eras 

 when the divergence between Aves and Reptilia 

 was not so wide as it is at the present time. 



In bringing the present chapter to a close a few 

 general remarks seem necessary upon what we may 

 term the philosophical aspect of the whole subject 

 of concealed or covered nests. In the first place, we 

 may begin by repeating the axiom that a bird's nest- 

 ing arrangements are in complete harmony, not only 

 with the peculiarities of its organisation but with the 

 special conditions of its existence. We may, there- 

 fore, fully rest assured that these nests dealt with in 

 the present chapter are concealed or covered from 

 some utilitarian motive. When we find certain means 



