CHAPTER IV 
GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION 
I, GEOGRAPHICAL DISTRIBUTION.! 
In considering the present distribution of mammals over the 
globe, we may, in the first place, direct our attention to terrestrial 
or land types, reserving the consideration of aerial types, like the 
Bats, and aquatic forms, as exemplified by the Cetaceans, Sirenians, 
and Seals, to separate sections. 
Among terrestrial forms each species has a certain definite area 
of distribution in space, which may be of very wide extent, or may 
be confined to a restricted region. This distributional area is, 
however, always connected, or continuous; that is to say, that 
although we may have a single species inhabiting two continents, 
like the Lion in Asia and Africa, or dwelling both on a continent 
and adjacent continental islands, like the Javan Rhinoceros of India, 
Java, and Borneo, yet we shall always find that such areas, if not 
still connected, show evident signs of having been so connected 
in comparatively late geological epochs; and we never find 
instances of the same species inhabiting totally disconnected areas, 
such as India and South America. As examples of mammals 
with a wide distribution we may mention the Lion and the 
Leopard, which are now found throughout Africa, and also occur 
in India, as well as in the intervening areas of Arabia and Persia. 
In the case of the former species, paleontology further teaches us 
that its distribution in the last geological epoch was even more 
extensive, since we have good evidence to show that it formerly 
ranged over the greater part of Europe, including the British Isles. 
The Jackal affords another well-known instance of a species common 
1 On this subject see A. Murray, Geographical Distribution of Mammals, 1866 ; 
and especially A. R. Wallace, The Geographical Distribution of Animals, 2 vols., 
1876, and Island Life, 1881; also A. Heilprin, The Geographical and Geological 
Distribution of Animals, 1887. 
