388 
ISLAND LIFE. 
[part II. 
Tertiary times the island was usually as large as, and often 
probably much larger than, it is now. 
Biological features of Madagascar . — Madagascar possesses an 
exceedingly rich and beautiful fauna and flora, rivalling in 
some groups most tropical countries of equal extent, and even 
when poor in species, of surpassing interest from the singularity, 
the isolation, or the beauty of its forms of life. In order to 
exhibit the full peculiarity of its natural history and the nature 
of the problems it offers to the biological student, we must 
give an outline of its more important animal forms in systematic 
order. 
Mammalia. — Madagascar possesses no less than sixty-six 
species of mammals — a certain proof in itself that the island 
has once formed part of a continent ; but the character of these 
animals is very extraordinary and very different from the as- 
semblage now found in Africa or in any other existing continent. 
Africa is now most prominently characterised by its monkeys, 
apes, and baboons ; by its lions, leopards, and hyaenas ; by its 
zebras, rhinoceroses, elephants, buffaloes, giraffes, and numerous 
species of antelopes. JBut no one of these animals, nor any 
thing like them, is found in Madagascar, and thus our first 
impression would be that it could never have been united with 
the African continent. But, as the tigers, the bears, the tapirs, 
the deer, and the numerous squirrels of Asia are equally 
absent, there seems no probability of its having been united 
with that continent. Let us then see to what groups the 
mammalia of Madagascar belong, and where we must look for 
their probable allies. 
First and most important are the lemurs, consisting of six 
genera and thirty-three species, thus comprising just half the 
entire mammalian population of the island. This group of 
lowly-organised and very ancient creatures still exists scattered 
over a wide area ; but they are nowhere so abundant as in the 
island of Madagascar. They are found from West Africa to 
India, Ceylon, and the Malay Archipelago, consisting of a 
number of isolated genera and species, which appear to main- 
tain their existence by their nocturnal and arboreal habits, and 
by haunting dense forests. It can hardly be said that the 
