264 THE RIVER-SIDE NATURALIST. 



are tapped, these are half-smothered, and float on the sur- 

 face of the water, and are caught by the country-people, 

 the streams or cuts being often depopulated ; yet before 

 the next spring the cuts again have their denizens, so that 

 the fish which come down from the hills not only increase 

 in size, but change their colour to suit circumstances. This 

 change of colour is very remarkable in some of the Con- 

 nemara streams. In the boggy portions ' bog-trout ' are 

 found, and in the others, above and below, ' silver-trout.' " 



Many other instances might be mentioned. Yarrell says : 

 " When we consider geologically the various strata traversed 

 by rivers in their course, the effect these variations of soil 

 must produce on the water, and the influence which the 

 constant operation of the water is likely to produce upon 

 the fish that inhabit it ; when we reflect, also, on the great 

 variety and quality of the food afforded by different rivers, 

 depending also on soil and situation, and the additional 

 effect which these combined causes, in their various degrees, 

 are likely to produce, we shall not be much surprised at 

 the variations both in size and colour which are found to 

 occur." 



The teeth in S. fario are in a double row on the vomer, 

 numerous, strong, and curved inwards. 



Fin-rays: dorsal, 12-15; pectoral, 13-15; ventral, 9; 

 anal, 10-12 ; caudal, 19. 



The river-trout is the prince of fresh-water fishes. 

 Yarrell describes it as " vigilant, cautious, and active ; " 

 Day, as " bold, voracious, cunning, and shy ; possessing 

 keen sight, and appears to be suspicious of anything 

 novel." We would give the trout a far better character, 

 and describe it as bold and determined, wary and watchful, 

 with its perceptive faculties much more developed than any 

 of its race. 



All living creatures which possess a brain, after coming 

 in contact with the human race generally become very shy 

 and wary. This has been particularly noticed with mammals 

 and birds ; then why should it not be so with fish ? 



The river-trout is the only species of our British 

 Salmonidce which when on the feed lies very near the 



