Distribittion 199 



Sweden, Siberia, Lapland, and in Algeria and 

 India; and migratory species along the shores 

 of Europe, Northern Asia, and even as far south 

 as the Crimea, and at the entrance of the harbor 

 of Sebastopol. From the geographical situa- 

 tion and climate of the Scandinavian Peninsula 

 it may be inferred that it is inhabited by a 

 greater number of species of salmonoids than 

 exist in other sections of the Continent or in 

 Great Britain. 



Constant additions are being made in the dis- 

 covery of new species or varietal forms, and in 

 the opinion of many European ichthyologists the 

 hybrids of the charrs and salmon-trouts are adding 

 to the number of confused and complicated spe- 

 cies, until Gunther, one of the most prominent 

 fish savants, is obliged to confess : — 

 . " We know no other group of fishes which 

 offers so many difiiculties to the ichthyologist, 

 with regard to the distinction of species as well 

 as to certain points in their life history as this 

 genus {Salmo). . . . The almost infinite varia- 

 tions of these fishes are dependent on age, sex, 

 and sexual development, food, and the properties 

 of the water. Some of the species interbreed, 

 and the hybrids mix again with one of the parent 



