ScHAKFF — On the Origin of the European Fauna. 471 



the climate, for when the cold passed away, the plaiu is believed not 

 to have suited the hare any more, and it retired to the more congenial 

 atmosphere of the mountain tops. This view, first promulgated, I 

 think, by Edward Forbes, has been almost universally adopted (see 

 p. 449). Certainly, as Darwin has remarked (p. 21a, 331), it explains 

 the presence of Arctic forms on the Alps and other mountains in a most 

 satisfactory manner. Still, I venture to think the Glacial Period did 

 not play so important a role in the present distribution of the Arctic 

 hare. We need only look at Ireland and at Sweden. In both countries 

 this hare inhabits the plain as well as the mountains. Moreover, it 

 flourishes in the former country where there is hardly any snow, and 

 where the temperature in winter approaches that of Southern Europe. 

 It seems to me unlikely, therefore, that this hare should have left the 

 plain of Central Europe and France, on account of the passing away 

 of the cold, and we must seek for other causes to explain its peculiar 

 geographical range. The European hare {Lepus europaeus) never 

 lived in Ireland, but it did inhabit Sweden, where it is now extinct. 

 Attempts have been made in both countries to introduce it, but 

 without success. On the other hand, we find it stated, in the 

 " Zoologia Danica " (97), that, in severe winters when the Sound 

 between Southern Sweden and Denmark becomes covered with ice, 

 the Arctic hare migrates across to the latter country. Nevertheless, 

 although this migration must have taken place on very numerous 

 occasions for centuries past, it has never been able to settle down in 

 the country, whilst the European hare thrives there. Both hares can 

 stand extremes of temperature perfectly well, but their range does 

 not overlap anywhere, and their distribution seems to me to indicate 

 that the two species will not live together. The European hare being 

 probably the stronger of the two, has driven the other out of the 

 European plain into the mountains, whilst in small colonies, as in 

 Ireland and Sweden, it may be overwhelmed by the superior numbers 

 of the enemy. Not the change of climate, but the sudden advent of 

 a [strong rival from the east probably confined the Arctic hare in 

 Central Europe to regions where, owing to the superior adaptability 

 of its fur to changes, of colour, it still reigns supreme, as a survival 

 indeed, but not of an Arctic climate. 



As I mentioned before, the Arctic hare is undoubtedly a very 

 ancient species and must have inhabited Europe before the European 

 hare made its appearance there. Had they arrived at the same time 

 from the east, there is no reason why both should not have reached 

 Ireland. The Arctic hare probably entered Asia from North America 



