342 



ISLAND LIFE 



PART II 



Latin Name. 



12. COREGONUS CLUPE- 

 OIDES 



13. 



14. 



VANDESIUS 



POLLAN 



English Name. 



The gwyniad, or 

 Schelly 



The vendace 



The pollan 



Locality. 

 Loch Lomond, Ulles- 

 water, Haweswater, 

 Red Tarn (Helvellyn), 

 Conningham mere 

 (Lancashire), Pemble 

 mere, near Chester, 

 and Bala lake. 

 Loch Maben, Dumfries- 

 shire, Derwentwater, 

 and Bassenthwaite 

 lake. 



Lough Neagh and Lough 

 Earne, N. of Ireland. 



These fourteen peculiar fishes differ from each other and 

 from all British and continental species, not in colour 

 only, but in such important structural characters as the 

 number and size of the scales, form and size of the fins, 

 and the form or proportions of the head, body, or tail. 

 Some of them, like S. killinensis and the Coregoni are in 

 fact, as Dr. GUnther assures me, just as good and distinct 

 species as any other recognised species of fish. It may. 

 indeed be objected that, until all the small lakes of 

 Scandinavia are explored, and their fishes compared with 

 ours, we cannot be sure that we have any peculiar species. 

 But this objection has very little weight if we consider 

 how our own species vary from lake to lake and from island 

 to island, so that the Orkne}^ species is not found in 

 Scotland, and only one of the peculiar British species 

 extends to Ireland, which has no less than four species 

 altogether peculiar to it. If the species of our own two 

 islands are thus distinct, what reason have we for believing 

 that they will be otherwise than distinct from those of 

 Scandinavia ? At all events, with the amount of evidence 

 we already possess of the very restricted ranges of many of 

 our species, we must certainly hold them to be peculiar 

 till they have been proved to be otherwise. 



The great speciality of the Irish fishes is very interesting, 

 because it is just what we should expect on the theory of 

 evolution. In Ireland the two main causes of specific 

 change — isolation and altered conditions — are each more 

 powerful than in Britain. Whatever difficulty continental 

 fishes may have in passing over to Britain, that difficulty 

 will certainly be increased by the second sea passage to 



