Evolution 



mammals ; for the sheep has proved itself splendidly adapted for 

 the conditions, and the rabbit most inconveniently so. Why, then, 

 this curious state of affairs ? It is an undoubted fact that the mar- 

 supials are both lower in their position in the animal kingdom, and 

 older, than the main group to which all our European mammals 

 belong. Now it is believed that Australia was once connected 

 by land with the Asiatic Continent, and that it was finally separ- 



FiG. 13. — Distribution of Lemurs. 



Madagascar . .12 Genera. 36 Species. 

 Africa, India, Malay. 5 Genera. 12 Species. 



ated from it before the higher mammals were in existence. The 



great step of further progress occurred elsewhere than in Australia, 



and the mammals of the latter continent were left in their obsolete 



condition, preserved through lack of competition of that higher 



type which elsewhere became dominant. 



Madagascar offers a similar case. It abounds with forest 



vegetation and seems to offer a highly suitable environment for 



the monkey tribe. Yet there are no apes on the island. Their 



place is occupied by the Lemur tribe, which, there is every reason 



18 



