CHAR 77 



lakes the Char differ so Httle from those of the 

 Lake District that they may be regarded as races 

 of 5. z^illughbii. But in a number of other lakes 

 they present such remarkable peculiarities, due to 

 their long-continued isolation, that they can only 

 be looked upon as distinct species. 



I am quite aware that some authors contend that 

 there is only one species of Char in our islands, 

 whilst some would not even recognize the various 

 forms as distinct races. Certainly our species of 

 Char are recent species and geographical species ; 

 they are of quite another nature from widely 

 distributed forms such as the Pike or Roach, 

 which have probably persisted unchanged during 

 the whole of the time that the evolution of the 

 Salvelini has proceeded. Nevertheless, they differ 

 from each other in characters which are used to 

 define species in other groups, and which may, 

 therefore, be regarded as specific. 



In fishes numerical characters are often of great 

 importance for the distinction of species, especially 

 as they are not subject to change during growth. 

 I have counted the vertebrae in various British and 

 Irish Char with the following result : — 



