THE TROPICAL FOREST 115 
for robbing man when they can, rather than limiting 
themselves to wild products. 
Not a few of the pigeons are arboreal. We may 
mention especially the fruit-pigeons, found in South- 
East Asia, and extending southwards to Australia. 
The bill is distensible at the base to permit the birds 
to swallow large fruits whole. 
Among the mammals we found that in addition to 
the truly arboreal forms there were a number like the 
chevrotains and agufis, which took advantage of the 
shelter afforded by the dense forest, through which 
their slender bodies permitted them to force their way. 
Quite similar conditions occur among the game birds, 
where various members of the pheasant family live 
in dense thickets, through which their wedge-shaped 
bodies enable them to travel easily. Such birds fly with 
considerable reluctance, preferring to trust to the thick 
cover unless danger approaches too closely. Among 
such forms we may mention the wood-partridges of the 
Malay region, the spur-fowl of India and Ceylon, the 
jungle-fowl, the guinea-fowl of West Africa, and so 
forth. 
Very remarkable is the condition presented by the 
hoatzin (Opisthocomus) of South America, where the 
young are hatched with claws on both the thumb and 
index finger, which they use in climbing about trees, 
after the fashion of a fruit-bat. The hoatzin is believed 
by some ornithologists to be related to the game-birds, 
but is a very primitive form. 
Among reptiles the crocodiles and their allies haunt 
the lakes and rivers of forest regions, where they lie in 
wait for the forest animals as they come down to drink. 
A very curious arrangement of the breathing organs 
enables them to drown their prey by holding the 
H 2 
