70 The Natural History of the Salmon, 



Giinther divides into two species: — i. Salmo fario 

 atisonii. 2. Salmo fario gaimardi. 



Another distinctive character in the salmon is 

 the position of the X spots. In the Sabno salar 

 these spots, with the exception of one or two, 

 are chiefly confined to the upper part of the 

 body, above the median hne. In the examina- 

 tion of many hundred salmon I have found this 

 to be the case, as a rule : the proportion of those 

 with any X spots below is very small indeed. 

 In the Sea trout, Salmo trutta, and all other species 

 and varieties the spots are equally distributed below 

 and above. The size and variety of the spots 

 depend on other circumstances, to be noted 

 further on. 



It is to be hoped that this confusion of varieties 

 with species, of hybridism, of the power of hybrids 

 to procreate, and of the ability of the male parr 

 to fructify the ova of the salmon, may soon be satis- 

 factorily cleared up. At present, after examining 

 thoroughly the various theories on both sides of the 

 question, it appears almost conclusive that the 

 Salmo salary Salmo trutta^ and Salmo fario, are 

 the three chief species of the genus Salmo, and 

 that many of the so-called species are nothing but 

 varieties arising from certain conditions produced 

 by external causes. 



Whether the true Salmo salar can be retained 



