NATURAL INCUBATORS 157 



fication, are only to be discovered in bird anatomy, 

 whereas they occur externally also. 



The Mound-birds always lay several eggs, and 

 always bury them ; but their procedure in this 

 respect varies : the Maleo simply inters them in 

 beaches of black volcanic sand, and is supposed to 

 deposit them in the hatching-holes at intervals of 

 a fortnight. The Brush-Turkey hens, however, 

 lay every two days, and the species of this family 

 generally scratch up mounds of earth, sand, and 

 dead vegetable matter, that of the Brush-Turkey 

 having a circumference of three dozen yards, with 

 a height of a little over two feet. 



In this species, as observed in captivity at all events, 

 the male does all the work of preparing the mound 

 and looking after the eggs, when laid and buried, 

 driving the hen or hens off as soon as they have 

 laid, and then covering them deeply or thinly as 

 occasion seems to demand. As many as twelve to 

 fifteen eggs may be laid by one of these birds, but 

 sometimes several pairs may share a mound, though 

 this seems not to be the case with the typical 

 Megapodii, which also use more sand and less 

 vegetable matter than the Brush-Turkey. The 

 latter bird breeds in the preserves of the Duke of 

 Bedford, and did so in the Zoo in a quite small 

 enclosure during the Bartlett period, and of late 

 years when Mr. Bertling was head-keeper. 



When hatched, the young scratch their way out 

 or are dug out by the old birds ; and not only are 

 they hardy when hatched, but their development 



