CHAPTER XVII 



THE CHAR AND THE SMELT 

 SUB-GENUS SALVELINUS 



REFERENCE has been made above to Dr. Giinther's arrange- 

 ment of the genus Salmo in two sub-genera : (i) Salmones, 

 or true salmon, distinguished by bearing teeth throughout 

 the length of the vomer; and (2) Salvelini, or chars, bearing 

 teeth only on the head or forepart of the vomer. It must 

 be owned that this is not a very convincing distinction, seeing 

 that the teeth on the vomer of the Salmones are not persistent 

 through life. As Dr. Giinther himself has explained, these 

 vomerine teeth " at an early age are gradually lost from behind 

 towards the front, so that half-grown and old individuals have 

 only a few (i 4) left." Still, the dentition of char is very con- 

 stant, and affords a convenient means of distinguishing between 

 two groups of the genus Salmo, which, although they have much 

 in common, differ pretty constantly in habit and appearance. 

 But whereas I find the same difficulty in understanding Dr. 

 Giinther's motive in subdividing the British char into six 

 separate species as presents itself against accepting his treat- 

 ment of fresh-water trout, I shall deal with the British char 

 as a single species branching into local varieties. Probably 

 agreement upon the number of species to be recognised among 

 the chars could only be arrived at after careful experiments, 

 consisting of rearing quantities of each variety and submitting 

 them to uniform physical environment, in order to test whether 



