CHAPTER IX. 



THE ORDEE OF SUCCESSION OF THE EEGIONS. — COSMOPOLITAN 

 GROUPS OF ANIMALS. — TABLES OF DISTRIBUTION. 



Having discussed, in our First Part, sucli general and preliminary 

 matters as are necessary to a proper comprehension of our 

 subject ; and having made ourselves acquainted, in our Second 

 Part, with the most important results of Palaeontology, we now 

 come to our more immediate subject, Avhich we propose to treat 

 first under its geographical aspect. Taking each of our six 

 regions in succession, we shall point out in some detail the chief 

 zoological features they present, as influenced by climate, vege- 

 tation, and other physical features. We shall then treat each 

 of the sub-regions by itself, as well as such of the islands or 

 other sub-divisions as present features of special interest ; en- 

 deavouring to ascertain their true relations to each other, and the 

 more important changes of physical geography that seem neces- 

 sary to account for their present zoological condition. 



Order of Succession of the Regions. — We may here explain 

 the reason for taking the several regions in a different succession 

 from that in which they appear in the tabular or diagrammatic 

 headings to each family, in the Fourth, and concluding part of 

 this work. It will have been seen, by our examination of extinct 

 animals (and it Avill be made still clearer during our study of 

 the several regions) that all the chief types of animal life appear 

 to have originated in tlie great north temperate or northern 

 continents ; while the southern continents — now represented by 



