276 DAYS AND NIGHTS OF SALMON FISHING 



ten in the salmon, fourteen or fifteen in the trout. 

 A line drawing shows how the counting is done. 



This method could, of course, be applied to the 

 distinction of parr and little trout, but it presents 

 difficulties as the scales are so small in both, and 

 the parr is, it is to be hoped, alive when the examina- 

 tion is being made, and is due to go on living. For 

 this emergency the test is even easier, and it consists 

 in looking at the mouth of the fish. The salmon, 



N 



Head of young Trout. Head of young Salmon. 



though it has bigger scales, is blessed with a smaller 

 mouth than a trout of the same size, and this is 

 particularly noticeable in the parr. The maxillary 

 bone in this little fish only comes to below the centre 

 of the eye. In a trout of the same size it will come 

 to below the hinder edge of the eye or even beyond 

 it. It is curious that in the very careful drawings of 

 parr and smolt which distinguish Scrope's book the 

 distinctive size of the mouth has not been properly 

 delineated. The accompanying line-drawing will, 

 I hope, make the point clear. The little fish shown 

 in Mr. Button's excellent photograph (p. xviii) 

 illustrate it also very well. 



THE END 



