102 THE FAUNA OF 
tion of structure seem to be associated with the fact 
that the lemurs here are protected by isolation, living 
as they do on an island where there are no true monkeys 
nor apes, and where the carnivores of the cat family 
are absent, members of the less differentiated civet 
alliance taking their place. 
Lemurs are less intelligent than monkeys, and much 
less highly differentiated, but they are no less definitely 
adapted to arboreal life. It is therefore the more 
interesting to find that, just as baboons are monkeys 
which have abandoned the arboreal life, so in Mada- 
gascar we find the ring-tailed lemurs, foxy-looking 
animals, which live among rocks in regions where trees 
are virtually absent. We have already spoken of the 
fact that the galagos of West Africa have an elongated 
ankle which, though the mechanism is a little different, 
gives them the power of leaping like a frog. The same 
peculiarity occurs in the mouse-lemurs (Chirogale) of 
Madagascar, and is even better developed in the little 
tarsier (Tarsius) of the Malay region, which progresses 
by leaping from one branch to another, or from one 
end of a branch to the other. 
We have not hitherto spoken of bats here, because 
those forms which occur in temperate regions show no 
special adaptation to any particular type of habitat. 
It is otherwise with the large fruit-bats, which are 
practically limited to the tropical regions of the Old 
World, where they are chiefly found in forests. They 
are entirely absent from the New World, but in the 
east extend southwards to the island continent of 
Australia and to Tasmania, though not to New Zealand. 
The fruit-bats are larger than the insect-eating forms, 
the common fruit or fox-bat of India measuring four 
feet from tip to tip of the wing. Their mastery of the 
