NOVEMBBE 265 



peculiar way, biting it and causing it to throw out a white 

 abnormal growth, which supplies the community with 

 their chief diet. 



XLIX 



Of all the infinite varieties of nest architecture none is 

 more strange and none more scientific than that Mound 

 practised by the Mega/podidce, or Mound Birds, ^^^ 

 of Australasia ; none is more hkely to set one speculating 

 upon the delimitation of instinct and reason, if, indeed, 

 there be any definite frontier between them, and if what 

 we revere as reason be not merely the fuUer exercise of 

 and evolution from that function or agency which the 

 older naturalists agreed to designate as instinct. 



The MegapodddcB embrace a group composed of three 

 genera confined to Australasia and the islands of the 

 Eastern Archipelago and Pacific. These genera contain 

 but few species, all distinguished by an extraordinary 

 development of legs and feet, which are speciahsed for 

 the purpose of a peculiar mode of nest-building. The 

 birds start at a considerable distance from the spot which 

 the hen has chosen to deposit her eggs ; walking back- 

 wards, they scrape together with their powerful feet all 

 the grass and leaves in their path, and pile them in a 

 heap, in the lower part whereof the large eggs are laid. 

 The process is continued until there is piled above the 

 eggs a mound of vegetable matter mingled with soil to 

 the aggregate weight of several tons. The most ambi- 

 tious architect is the Australian megapode {Megapodius 

 tvmmlus), a pair of which, although they are no larger 

 than Dorking fowls, have been known to construct a 

 mound measuring 150 feet in circumference. This, 



