tRELIMiNARY CONSIDERATIONS. ?I 



When the snow-fields, as in the Alps, were much 

 more extensive than they are at present, the glaciers 

 which radiated from them would be more sensitive 

 to minor climatal change. Even now they oscillate 

 considerably. But during a Glacial epoch, an inch, 

 either more or less, of precipitation might mean a 

 considerable advance or retreat of the ice in the low- 

 lands." French geologists look with even less favour 

 on Professor Geikie's theories. Mr. Falsan (p. 212) 

 says that he agrees with Messrs. Favre, de Saporta, 

 Lory, de Mortillet, Desor, de Lapparent, Lortet, 

 Chantre, Benoit, Fontannes, Deperet, and many 

 other geologists, that there was only a single Glacial 

 period, which, according to each particular region, 

 might be divided into several phases, or into their 

 equivalents viz., one or more extensions of the 

 ancient glaciers. But, on the whole, the view that 

 there was at least one inter-glacial phase in the 

 Glacial period meets with more general acceptance 

 among geologists, I think, though the other opinion 

 agrees much better with the nature of the fauna 

 and flora as it has been revealed to us from the 

 pleistocene deposits. 



The occurrence of the remains of such arctic species 

 of mammals as the Musk-Ox, Arctic Fox, Glutton, 

 Lemming, and many others in these deposits, is 

 frequently held up to us by geologists as a proof 

 of the prevalence of an arctic climate while these 

 beds were laid down. And indeed this appears 

 at first a most satisfactory explanation of the 



