THE CALIFORNIAN SALMON. 
107 
THE IDENTIFICATION OF SALMON AND 
TKOUT. 
When the soldiers of Caesar in their victorious march 
upon Gaul and Britain, reached the banks of the Garonne, 
the saltatory motions of a fish new to them, making his 
ascent from the sea, obtained for him the specific name, 
that his habits so well justify to the present day, as may be 
well seen in any river where salmon abound ; this fish being 
able to leap ten or twelve feet high in ascending waterfalls 
on the way to its spawning ground. The Salmo salar is 
admittedly the king of fishes but there are princes and 
nobles of the family, which bear such a close resemblance 
to him, that the identification of individuals is in some 
cases a matter of great difficulty. 
The genus Salmo presents such diversity of form, caused 
by differences in food, climate, circumstances, and the 
quality of the water of the streams and rivers in which 
the specimens are found, that the icthyologist sometimes 
finds the determination of the identity of individual speci- 
mens of the genus, a most difficult problem to solve. The 
difficulties are greater also, from the development of the 
sexual characters materially changing the appearance of the 
fish at certain seasons, the colour differing most markedly 
at the breeding season, and in the males, the cartilaginous 
protuberance which is then formed on the under jaw, 
completely alters their appearance. Added to this is the 
ascertained fact, that many, if not all, of the species are 
capable of hybridisation, and the hybrids have in some 
cases been found to be capable of propagating their kind, 
and of again crossing with the pure race. Hence it is not 
improbable, that there are intermediate forms connecting — 
in many cases — the different genera, and rendering identi- 
fication difficult, if not impossible. The crosses between 
