Ornithology of Northei-n Celebes. 145 



being very long and greatly curved. The toes are, however, 

 slightly webbed at the base, and thus the whole foot and rather 

 long leg are well adapted to scratch away rapidly a loose sand, 

 although they could not, without much labour, accumulate the 

 heaps of miscellaneous materials which the large, grasping feet 

 of the Megapodii bring together. 



The very peculiar habits of the whole family of the Megapo- 

 diida departing widely from those of all other birds, may also, 

 I think, be shown to be almost the necessary results of certain 

 peculiarities of organization. These peculiarities are two — the 

 size and number of the eggs, and the nature of the food on which 

 these birds subsist. Each egg being so large as to fill up the 

 abdominal cavity and with difficulty pass the walls of the pelvis, 

 a considerable interval must elapse before the succeeding ones 

 can be matured. The number of eggs which a bird produces 

 each season seems to be about eight, so that an interval of three 

 months elapses between the laying of the first and last egg. 

 Now, supposing the eggs to be hatched in the ordinary way, 

 they must be laid on the ground (for the general structure of 

 the bird renders the construction of an arboreal nest impossible) 

 and must be incessantly watched by the parents during that 

 long interval, or they would be surely destroyed by the large 

 lizards which abound in the same district. It seems probable, 

 however, that the eggs could not retain the vital principle for so 

 long a time, so that the bird would have to sit on them from the 

 commencement, and hatch them successively. But the period of 

 incubation is a severe tax upon all birds even when it is com- 

 paratively short and food easily obtained. In this case complete 

 incubation would be most likely impossible, because the parti- 

 cular species of fruits on which these birds subsist would be soon 

 exhausted around any one locality, and both parents and ofi"spring 

 would perish of hunger. If this view is correct, the Megapodiidce 

 must behave as they do. They must quit their eggs to obtain 

 their own subsistence, — they must bury them to preserve them 

 from wild animals, — and each species does this in the manner 

 which shghter modifications of structure render most convenient. 



It has been generally the custom of writers on natural history 

 to take the habits and instincts of animals as the fixed point, and 



