chap, xi.] THE ETHIOPIAN REGION. 287 



and helped to form a great southern continent which must at one 

 time have extended eastward as far as Southern India and 

 Ceylon ; and over the whole of this the lemurine type no doubt 

 prevailed. 



During some portion of this period, South Temperate Africa 

 must have had a much greater extension, perhaps indicated by 

 the numerous shoals and rocks to the south and east of the 

 Cape of Good Hope, and by the Crozets and Kerguelen Islands 

 further to the south-east. This would have afforded means for 

 that intercommunion with Western Australia which is so clearly 

 marked in the flora, and to some extent also in the insects of the 

 two countries ; and some such extension is absolutely required 

 for the development of that wonderfully rich and peculiar 

 temperate flora and fauna, which, now crowded into a narrow 

 territory, is one of the greatest marvels of the organic world. 



During this early period, when the great southern continents 

 — South America, Africa, and Australia — were equally free from 

 the incursions of the destructive felines of the north, the 

 Struthious or ostrich type of birds was probably developed into 

 its existing forms. It is not at all necessary to suppose that 

 these three continents were at any time united, in order to 

 account for the distribution of these great terrestrial birds ; as 

 this may have arisen by at least two other easily conceiv- 

 able modes. The ancestral Struthious type may, like the 

 Marsupial, have once spread over the larger portion of the globe ; 

 but as higher forms, especially of Carnivora, became developed, 

 it would be exterminated everywhere but in those regions 

 where it was free from their attacks. In each of these it would 

 develope into special forms adapted to surrounding conditions; and 

 the large size, great strength, and excessive speed of the ostrich, 

 may have been a comparatively late development caused by its 

 exposure to the attacks of enemies which rendered such modi- 

 fication necessary. This seems the most probable explanation 

 of the distribution of Struthious birds, and it is rendered almost 

 certain by the discovery of remains of this order in Europe in 

 Eocene deposits, and by the occurrence of an ostrich among the 

 fossils of the Siwalik hills ; but it is just possible, also, that the 



