Mr. G. R. Gray on the Family Megapodide. 73 
and when deposited must cover it with some portion of the sand 
which is around it, and thus by degrees the interior of the hole be- 
comes mostly filled in, after which the place of concealment is often 
betrayed by the birds scratching over it a large heap of such shells and 
rubbish as they may meet with on the beach. The eggs are then 
left to be hatched by the heat engendered in the sand through the 
rays of the tropical sun playing on its surface; probably a longer 
period for hatching the eggs is required than from the heat caused 
by the fermentation of decaying vegetable matter, the heat of which 
is known to be considerable. 
Thus, if the preceding statement is correct, the eggs in one hole 
have been laid and the hatching of them has commenced about the 
same time ; and therefore it may be concluded that, after the neces- 
sary time has elapsed, all the young birds are likely to make their 
appearance about the same period. 
It has been previously stated in reference to some of the mound- 
raising species (T'alegallus, Leipoa) that the eggs are placed by the 
bird in a circle. The mode thus adopted by the bird is interestingly 
accounted for by His Excellency Sir George Grey, in the following 
manner :—After the bird, he says, has deposited the first ege 
in the sand, leaving from 4 to 6 inches between the lower end of the 
egg and the layer of dead leaves, it then lays the second egg, which 
is ‘‘ deposited in precisely the same plane as the first, but at the op- 
posite side of the hole before alluded to. When the third egg is 
laid it is placed in the same plane as the others, but, as it were, at the 
third corner of a square. When the fourth egg is laid it is still 
placed in the same plane, but in the fourth corner of the square, or 
rather of the lozenge, the figure being in this form *§-. The next 
four eggs in succession are each placed in the interstices, but always 
in the same plane ; so that at last there is a circle of eight eggs all 
standing upright in the sand with several inches of sand intervening 
between each.” 
Other species do not regard such mathematical principles in the 
laying of their eggs, but place them irregularly anywhere within the 
mound, or in whatever position the several species may instinctively 
adopt, as previously explained. That they may obtain the heat re- 
quired to bring them to maturity appears to be the principal object. 
It seems marvellous that these birds, after they have taken all 
these precautions for the preservation and development of their eggs, 
should exhibit no further care for them, but leave the young entirely 
to find for themselves their way out of whatever position the females 
may have placed the eggs in. The young bird, on breaking the 
shell, scratches its way out of the heap without any assistance, and 
when free, just shakes off the material of which the heap had been 
composed, and then runs off to the thickets, &c., and commences 
seeking its food without any hesitation, by scratching and turning 
up the earth or débris that lie on it, like an old bird. Each bird is 
fully fledged on its first appearance. This latter circumstance has 
caused some collectors and ornithologists to suppose these young 
birds to be the adult state of a species; and the idea has occasioned 
