A STUDY ON TROUT AND YOUNG SALMON. 255 



In description of the general image of the species, the means, 

 by wich the description is to be effected, will consequently be 

 dependant on the nature oE the peculiarities and give due consi- 

 deration to these. 



If we place before us an adult salmon and an adult trout 

 place them side by side and ask. by wich means we distinguish 

 them, I should decidedly answer: by means of „habitus", the 

 image, presented by the total of their exterior characters. The 

 main difference by means of wich I am able, even at first sight, 

 to distinguish between them is shortly this: 



The body of the salmon is considerably more slender and spool- 

 shaped than that of the trout, wich is more plump and clumsy. 

 The tail of the salmon is considerably longer more coniccylin- 

 drical and lower than that of the trout, wich is shorter higher and 

 more compressed from the sides. 



The caudal fin of the salmon is more cut out than that of 

 the trout. The anal fin of the salmon is smaller and the scales 

 of the body are larger than those of the trout. 



The trout is not so shiny and silver coloured and has 

 more dorsal and lateral spots than the salmon. Behind the 

 dorsal fin the salmon is spotted only above the lateral line. 

 The trout is spotted also below the lateral line. The upper jaw 

 of the salmon is shorter than that of the trout. 



All these factors and their mutual relations form the main 

 features of the image, wich at all times enable us to distinguish 

 the two species. Even in the fry (parr) stage and when in a 

 state of maturety, stages in wich the fishes considerably differ 

 from (he species as grown up, but not yet mature, a number of 

 the abovmentioned factors, such as the lenght of the upper jaw, 

 the form of the body, the ralations of fins and tail besides the 

 size of the scales, form a valueable clue for distinction, a clue 

 wich is also strengthened by other factors peculiar to these 

 stages. 



