54 The Natural History of the Salmon, 



migratory trout have two (and even three) more 

 than the river trout. In some waters, river trout 

 remain small, and frequently retain the parr marks 

 all their lifetime. At certain seasons a new coat 

 of scales overlays the Parr marks, rendering them 

 invisible for a time, but they reappear in time, or 

 are distinct as soon as the scales are removed. When 

 the Salmones have passed this Parr state the colora- 

 tion becomes much diversified. The males especi- 

 ally, during and immediately after the spawning 

 time, are more intensely coloured and variegated 

 than the females, specimens which have not attained 

 to maturity retaining a brighter silvery colour, and 

 being more similar to the female fish. Food appears 

 to have less influence on the coloration of the outer 

 parts than on that of the flesh ; thus the more varie- 

 gated are frequently out of condition, whilst well-fed 

 individuals with pinkish flesh are of a more uniform 

 though bright coloration. Chemistry has not sup- 

 plied us yet with an analysis of the substance which 

 gives the pink colour to the flesh of many Sal- 

 monoids ; but there is little doubt that it is identical 

 with, and produced by, the red pigments of many 

 salt and fresh water Crustaceans which form a 

 favourite food of these fishes. The water has a 

 marked influence on the colours ; Trout with intense 

 ocellated spots are generally found in clear rapid 

 rivers, and in- small open alpine pools ; in the large 



