52 The Scottish Naturalist. 



extinct as a wild beast, as Mr Alston has not been able to 

 find any records later than 1263. 



For the occurrence, in historic times in Scotland, of the Beaver 

 {Castor fiber L.), the evidence is not very satisfactory, though 

 three Gaelic names survive ; and there was a tradition that 

 Beavers inhabited one river in the twelfth century, at which 

 time they had not become extinct in Wales. 



Of the remaining extinct Scottish species the Elk (A/ces 

 machlis Ogilby) and the Reindeer (Rangifer tarandus L.) were 

 probably the latest survivors, and may have lingered on to 

 historic times, though that is somewhat doubtful. There is no 

 doubt, however, that they colonised Scotland after the close of 

 the glacial period, as did also the Bos longifroiis (probably the 

 ancestor of the modern short-horned cattle), the Urus (Bos pri- 

 migeniits Boganus — the progenitors, according to some authors, 

 of the White Cattle of Cadzow and Chillingham, which Mr 

 Alston does not believe), the Irish Deer (Megacei-os giga?iteus 

 Blumenbach), the Horse (Equus caballus L.), and possibly the 

 Mammoth (Elephas primigenius Blumenbach). The evidence 

 for the post-glacial existence of the latter and of the Irish Deer 

 in Scotland is not quite so strong as might be wished. 



In tracing the distribution both of the living and extinct 

 mammalia, Mr Alston has been at considerable pains to ascer- 

 tain w 7 hat species are or have been indigenous in the various 

 islands that lie off the west and north of Scotland. Putting 

 aside the aerial and marine mammals (bats, seals, and cetaceans) 

 and the introduced domestic species (the common mouse and 

 the two rats), twenty-four living terrestrial species are left, all of 

 which occur on the mainland, — seven reach the inner islands, 

 six attain the outer islands, seven (including two now extinct 

 in the islands) are recorded from Orkney, and only one from 

 Shetland. These numbers do not include certain species intro- 

 duced by human agency, nor others for whose occurrence more 

 evidence is required. Of the twenty- four species twelve occur 

 in Ireland. From this distribution Mr Alston arrives at an 

 ingenious theory as to the time and order of the arrival in 

 Scotland of the various species. First stating that Professor 

 Leith Adams has shown that both the recent and extinct Irish 

 mammals agree with those of Scotland rather than of England, 

 and that there is reason to suppose that Ireland received that 

 part of its fauna from the south of Scotland, after the separa- 

 tion (of Ireland) from Wales and western England, Mr 



