NATURAL REGIONS OF THE GLOBE 13 



Europe and North America, and of the animals of the 

 Mediterranean or scrub forest, found round the Mediter- 

 ranean Sea, in Cahfornia, and elsewhere. We shall find, 

 however, that such regions have for the most part 

 a transitional fauna, made up of units from the sur- 

 rounding regions, and that further they have been 

 much altered by man's interference. It is true that the 

 effects of this interference are often interesting, for 

 while some animals die out as civilization spreads, 

 others, like the rats, the common sparrow, the cock- 

 roaches, some parasites, and so on, adjust themselves 

 to the altered conditions, and prosper under civiliza- 

 tion as they never did in former days. But a considera- 

 tion of these points would take us too far from our 

 immediate subject. We shall therefore confine our- 

 selves to a consideration of the nine natural regions 

 already given, and fill up whatever gaps this method 

 may leave by a final consideration of the zoogeogra- 

 phical regions into which zoologists have divided the 

 globe. But as the greater part of this book is thus 

 devoted to the geographical aspect of animal distribu- 

 tion, a word or two may be added in further explanation 

 of the difference between the two points of view, the 

 zoological and the geographical. 



To the zoologist it is a fact of great interest 

 that the sloths, ant-eaters, and armadillos should 

 occur in South America, and nowhere else. But the 

 geographer is more interested in the fact that the sloth 

 is a purely arboreal animal, fitted only for life in the 

 dense forest, while the armadUlo, for example, shows 

 adaptations to quite other habitats. The difference 

 between the sloth of the Amazon forest and the squirrel 

 of the Siberian taiga, again, means something very 

 different to zoologist and geographer, for the latter 



