i899-1 The History of the European Fauna. 245 



Rhytina and many Whales have survived longest in regions near one or 

 other of the poles, and it may be that similar reasons explain the 

 extreme southern habitat of the Penguins. The Reindeer, the Musk Ox, 

 the Polar F'ox, and the Lemmings, have only retired northwards in recent 

 periods, and may well have been driven from the more southern regions 

 which the}' formerly occupied — the larger animals, perhaps, by man, the 

 lesser by the competition of other forms. Lastly, where competition 

 is less keen, as in islands and peninsulas, northern forms occur very 

 much to the south of their ordinary range, witness the Reindeer and 

 Arctic Fox in Kamchatka, and the Varying Hare, which is able to 

 live at sea-level in Ireland in the absence of the competition of the 

 larger Lepus europcmis. But amongst these Arctic animals we must surely 

 recognize the presence of a few members of dominant groups which 

 spread and maintain themselves in all latitudes almost regardless of 

 climate, and amongst them I would include the Stoat, found widely 

 distributed in one form or another, and the Polar Bear, a species of a 

 very dominant genus. 



The members of Dr. Scharff's Siberian migration hardly reached 

 westward of the east coast of England. It has left numerous survivors 

 on the continent, and nine, including the extinct Beaver, in England. 

 The Polecat, the Harvest Mouse, the Hamster, and the Brown Hare are 

 instances of this group, with regard to which, Dr. Scharff, arguing mainly 

 from Mollusca, upon which it appears the Glacial Period had hardly any 

 effect (p. 196), and disagreeing with Prof. A. Nehring (pp. 210 and 211), 

 is at some pains to show that it was not characteristic of steppe-like 

 conditions. But surely what might be true of mollusca need not 

 necessarily be so of mammals. The former, powerless to move from their 

 haunts, might survive unhurt a short continuance of wholly changed 

 conditions ; the latter, with their ready means of locomotion and high 

 intelligence, would readily follow on the heel of conditions which suited 

 them best, so that it really needs no great Siberian migration to account 

 for their presence in Western Europe. Appropriate mammals would 

 necessarily fill up a treeless region, wherever such existed, and would as 

 quickly retreat before the advent of forests. If, as Dr. Scharff supposes, 

 the west had always the wetter and milder climate, then that is sufficient 

 to account for the failure of the Siberian forms to penetrate to Ireland, 

 but some of them must have got very near to our inaccessible shore, for 

 we have the Common Shrew in Jura, and the Brown Hare in the otherwise 

 quite hibernian Isle of Man. 



We must at this point enter a protest against Dr. Scharff's use of the 

 word " migration." The fact is that by many people the word migration 

 is used in a very careless and loose sense to indicate what are three 

 distinct sets of phenomena — we mean the ordinary periodic and seasonal 

 movements of migratory birds, fishes, or other animals; the extraordinarj r 

 and often evanescent irruptions of animals like the Sand-Grouse and the 

 Lemming ; and the steady, almost imperceptible dispersion of a species 

 such as the gradual recent increase of the Woodcock and Starling as 

 breeding species in the South of Ireland. There are statements in his 

 book indeed, as where he states that the first and third of these 



