THE 



EDINBURGH 



PHILOSOPHICAL 



NEW 



JOURNAL 



On some Anomalies in Zoological and Botanical Geography. 

 By Alfred E. Wallace. 



The subject of Geographical Distribution is now gene- 

 rally allowed to be one of the most interesting branches of 

 Natural History, and owing to the accumulation of much 

 trustworthy material within the last few years, we are at 

 length enabled to generalise many of the most important 

 facts, and to form a tolerably accurate idea of the import 

 and bearing of the whole inquiry. 



In the admirable chapters on this topic in the " Origin 

 of Species,'' Mr Darwin has given us a theory as simple as 

 it is comprehensive, and has besides gone into many of the 

 details so fully as to render it needless to say another word 

 here on those parts of the question which he has treated. As 

 an explanation of the main facts, and of many of the special 

 difficulties, of geogra]Dhicai distribution, those chapters are 

 in every respect satisfactory ; and I therefore propose now 

 to consider only the anomalies and discrepancies which so 

 frequently occur between the distribution of one class or 

 order and another, and to discuss the possibility of arriving 

 at a division of the earth into Eegions, which shall repre- 

 sent accurately the main facts of distribution in every de- 

 partment of nature. 



In doing this I shall consider in detail a few cases of 

 special difficulty only, and endeavoijr to establish certain 



NEW SERIES. VOL. XIX. NO. I. JANUARY 1864. A 



