1913-1914.] 49 



to a strictly terrestrial life. We need not consider the first two 

 divisions — the swimmers and the flyers — for it is quite conceivable 

 that they may have crossed to Ireland without its ever having 

 formed part of Great Britain and the Continent. Then again, 

 among the sedentary Mammals, there are certain species, such as 

 the Mice and Rats, which may possibly have been introduced into 

 this country by man. Others can be clearly recognised as having 

 formed part of a great independent invasion of Ireland. Neither 

 winds nor sea currents could have carried them across the water. 

 And man certainly did not introduce them. Such are, for 

 example, the Irish Stoat, the Marten, the Hedgehog, and the 

 Badger. The first mentioned animal, moreover, although a near 

 relation of the English Stoat, is quite distinct from it. All these 

 species have been found fossil in Ireland, along with the remains 

 of animals long since extinct in this country. Their ancestors 

 must, therefore, have reached Ireland a great many centuries ago. 



The general ranges of the common Stoat, Marten, Hedgehog, 

 and Badger in Europe are very much alike. Let us examine, for 

 instance, that of the last mentioned animal. You will notice from 

 the map showing its distribution that this animal inhabits the 

 greater part of Europe, except middle and northern Russia and 

 northern Scandinavia. This fact suggests that the Badger 

 originally came from the south. But nowhere in southern Europe 

 are Badger remains found in the older Tertiary deposits. On the 

 other hand, in the Pliocene beds of Persia we meet with several 

 species allied to our Badger. The fossil evidence is in favour, 

 therefore, of a south-eastern origin of the Badger, and here also 

 lies the centre of its geographical distribution, for it ranges far 

 into eastern Asia. From this centre of evolution we may suppose 

 that Badgers have spread east and west to colonise Asia and 

 Europe. 



Besides the four kinds of animals alluded to, which may be 

 looked upon as representatives of a group that are not liable to 

 accidental dispersal, there are others in Ireland belonging to this 



D 



