46 The Irish Naturalist. February, 



form has been independently evolved in its Irish and Scottish habitats, 

 and possibly also in Portugal, where a specimen, apparently referable to 

 the same variety, has been obtained. 



On the other hand, the island of Lewis possesses another sub-species, 

 Mus s. hebridensis, found as yet only in that island and Barra, which 

 varies from the prevailing British form {Mus s, intermedws) in an opposite 

 direction to Mus celticus : — for M. hebridensis is a larger animal than 

 M. intermedins, with relatively smaller ears, and has the colours of its 

 upper and lower surfaces less contrasted ; whereas M. celticus is smaller 

 than M. intermedins, has relatively larger ears, and is even more strongly 

 contrasted in the hues of its upper and lower surface. 



The co-existence of two such unlike varieties in a small area like that 

 of the island of Lewis, throws difficulties in the way of imagining a 

 direct climatic stimulus towards the M. celticus type in the Outer 

 Hebrides. Moreover, the Field Mouse of St. Kilda (Mus. hirtensis, 

 Barrett-Hamilton) closely approaches M. hebridensis, and is, therefore, 

 widely divergent from M. celticus. These facts undoubtedly possess a 

 high zoological value, and Mr. Barrett-Hamilton deserves much credit 

 for having worked them out in so painstaking a manner ; but we think 

 it would be premature, in the present state of our knowledge, to draw 

 conclusions as to their interpretation, since the influence of the 

 Hebridean climate can hardly be held answerable for two sets of varia- 

 tions running in diametrically opposite directions, and without the 

 exertion of some such influence it is difficult to conceive of the same 

 variation being independently evolved in several scattered localities. 



In a shorter paper Mr. Barrett-Hamilton treats of the various forms of 

 Lepus timidus, the Variable or Mountain Hare. He maintains that there 

 are two very distinctly-coloured groups of this species. The form to 

 which the Scottish and South Scandinavian mountain-hares belong he 

 distinguishes as Lepus timidus tjpicus, and the Irish hare as L. t. hibemicus 

 It is curious that the latter should find its nearest ally (Z. t. altaicus) in 

 the distant regions of the Altai mountains. Its reddish-brown (rather 

 than dark brown) colour, slightly larger size, and general absence of a 

 complete white winter coat, are the principal characteristics of the 

 Irish Hare as distinct from that of Scotland. The point of interest for 

 Irish naturalists is the question how these differences may have 

 originated ; whether by evolution within the limits of this island since 

 its severance from Britain, or otherwise — as from two different races 

 having immigrated into the British area at different periods. As the 

 points of distinction are not very decisively marked, the former solution 

 seems the more probable ; but, as in the case of the Field-Mouse, the 

 materials do not warrant a positive conclusion. 



Naturalists who shrink from excessive ,r splitting" will be shocked 

 to learn that Mr. Barrett-Hamilton bestows a third or quasi«subspecific 

 name {Lepus timidus lutescens) on the Hare of the Mqlahide district, 

 Co. Dublin — which, he thinks, " may perhaps be best regarded as a very 

 conspicuous aberration on the verge of becoming subspecific." 



C, B. M, 



