The Natwal History of the Salmon. 67 



most constant among the two first generic groups 

 in the genus Sahno, I arrive at the conclusion that 

 most of them are fallacious, and that too great a 

 stress having been placed upon them, many errors 

 have resulted. The consequence has been that the 

 number of species has been unduly augmented, and 

 local races have been accorded generic rank, inter- 

 mediate forms have not been searched for ; but new- 

 ones constantly hunted up. Thus the synonymy 

 will be the cause of endless confusion to future 

 ichthyologists. Besides this, every little variety of 

 form, colour, or structure, has been accounted for by 

 terming such hybrids." (" The Fishes of Great 

 Britain and Ireland," vol. ii. p. 59.) 



As regards this hybridism, which no doubt does 

 often occur, very little is yet known ; but the experi- 

 ments now going on under the superintendence of 

 Dr. Day will probably throw great light upon this 

 subject. 



Dr. Francis Day has gone largely into the study 

 of the Salmonoids, and I would advise all who 

 take an interest in the subject to read his observa- 

 tions. 



It appears that although many of these characters 

 are not to be relied on as being not sufficiently 

 persistent, and dependent on locality, food, etc., 

 yet there are others, which are more constantly 

 permanent, viz. — the teeth on the vomer and the X 



