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 Trichoglossidee, 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 Paradiseidse (birds of paradise and allies) am 

 another remarkable family, confined to the Papuan group of 

 Islands, and the tropical parts of Australia. The Megapodiidse 

 (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 

 Vol. I.— 27 



