II. 



The Climate of Europe during the Glacial 



Epoch. 



CLIMATIC changes in byegone times may account for many 

 peculiarities in the present geographical distribution of animals 

 and plants. The last " Glacial Epoch," however, has been held 

 responsible for so many anomalies, that it is not surprising to find 

 the more cautious naturalist somewhat chary of referring anything to 

 this cause. Still, it is impossible to doubt that important changes of 

 climate have taken place within the lifetime of existing species, and 

 that these climatic changes necessarily led to much extermination 

 and forced migration. Evidence of this may be found, no doubt, in 

 the present distribution of animals and plants ; but clearly to under- 

 stand the origin of the existing faunas and floras, we must first 

 master the outlines of their former distribution. We must learn, 

 also, what climatic and orographic changes have taken place, and 

 what parts of the world these changes affected. 



All this may seem self-evident. But though biologists now 

 understand that embryology is essential, and that the study of extinct 

 forms cannot be neglected, yet the writer on geographical distribution 

 is often content to speculate on what may have been, without 

 reference to the geological evidence as to what really did happen. 

 It is as if we read our history, like a witch's prayer, backwards ; or 

 as if, in writing a biography of a celebrated man, we commenced 

 with his funeral, or described nothing but his last moments. Such a 

 method of studying history would be absurd ; but it is the method 

 often adopted in natural history. 



A rapidly increasing body of naturalists recognises, however, 

 that there is an evolution of faunas and floras to be studied, as well 

 as an evolution of species. For the benefit of these naturalists it 

 may be useful to summarise the present state of our knowledge of 

 fhe later Tertiary changes in Western Europe. This I venture to 

 do ; but it must be confessed that we are as yet merely commencing 

 a very large enquiry, and that unexpected and often puzzling pieces 

 of evidence are met with daily. We shall ultimately, I hope, be able 

 to write a fairly continuous epitome of the most recent chapter in the 

 earth's history ; at present we can only deal with more or less 



