CHAP. XIII.] THE AUSTRALIAN REGION. 393 
varied forms of life in the Oriental region ; to which, possessing 
great powers of flight, some species must occasionally have emi- 
grated. Its presence or absence serves therefore to define and 
limit the Australian region with a precision hardly to be 
equalled in the case of any other region or any other family of 
birds. 
The Trichoglossidz, as already intimated, are another of these 
peculiarly organized Australian families,—parrots with an ex- 
tensile brush-tipped tongue, adapted to extract the nectar and 
pollen from flowers. These are also rigidly confined to this 
region, but they do not range so completely over the whole of it, 
being absent from New Zealand (where however they are repre- 
sented by a closely allied form Nestor), and from the Sandwich 
Islands. The Paradiseide (birds of paradise and allies) are 
another remarkable family, confined to the Papuan group of 
Islands, and the tropical parts of Australia. The Megapodiidee 
(or mound-builders) are another most remarkable and anomalous 
group of birds, no doubt specially adapted to Australian con- 
ditions of existence. Their peculiarity consists in their laying 
enormous eggs (at considerable intervals of time) and burying 
them either in the loose hot sand of the beach above high-water 
mark, or in enormous mounds of leaves, sticks, earth, and refuse 
of all kinds, gathered together by the birds, whose feet and 
claws are enlarged and strengthened for the work. The warmth 
of this slightly fermenting mass hatches the eggs; when the 
young birds work their way out, and thenceforth take care of 
themselves, as they are able to run quickly, and even to fly short 
distances, as soon as they are hatched. This may perhaps be an 
adaptation to the peculiar condition of so large a portion of 
Australia, in respect to prolonged droughts and scanty water- 
supply, entailing a periodical scarcity of all kinds of food. In such 
a country the confinement of the parents to one spot during the 
long period of incubation would often lead to starvation, and the 
consequent death of the offspring. But the same birds with free 
power to roam about, might readily maintain themselves. This 
peculiar constitution and habit, which enabled the Megapodii to 
maintain an existence under the unfavourable conditions of their 
Vout. L—27 
