282 THE ZOOLOGIST. 



muscles are of great power, a provision which enables it to over- 

 come the cataracts and cascades of rivers, for, curving itself, it 

 suddenly contracts the muscles of the convex side and throws its 

 weighty body out of the water to a considerable height. When 

 fancy held its sway in natural history, the older authors suggested 

 that it rested its body on a rock, or in other cases put its tail in 

 its mouth so as to get full benefit of the sudden muscular 

 contraction in its leaps. This muscle has a characteristic tint 

 from the oil, and the same hue is present in the globules which 

 occur below the blastoderm in the developing egg. As in other 

 fishes these great muscles long retain their irritability, so that 

 by making slits and immersing the fish in cold water a stale fish 

 is rendered firm. 



Like most fishes the Salmon is a predatory form, yet little 

 or no food has been found in its stomach in fresh water, a fact 

 which has led to various explanations by the public and by 

 scientific men. Thus Prof. Owen at one time thought that, in 

 common with many other fishes when hooked or netted, it 

 emptied its stomach by an instinctive act of fear or to facilitate 

 escape by lightening its load, leaving only minute animalcules in 

 the gastric mucus. But, as pointed out long ago, if this were 

 the rule, the intestine would be well filled, since the Salmon 

 cannot eject its food after it passes the pylorus ; moreover, 

 the very terror which impels the action in one fish may 

 paralyze the efforts in another. Investigations in the Tay 

 below Perth from the Tents Moor upward 6how that many 

 Sand-Eels, Sprats, Herrings, crustaceans, disintegrating muscular 

 tissue, lime-crystals, and the ordinary chymous mass occur in 

 the stomach of certain Salmon which probably fed in the sea or 

 in the estuary. Sand-Eels, indeed, form a favourite bait in the 

 sea for Salmon, and it is stated that in Sutherland hooks baited 

 with this fish are attached to a bladder which is allowed to 

 float up a narrow firth for its capture. The contrast with such 

 as the Sparling and the Salmon-Trout, which are both caught by 

 nets, is marked, for their stomachs are generally well filled. 

 The Salmon, indeed, does not feed in fresh water, the fat and 

 other materials stored in its muscles and viscera sufficing for the 

 full development of its reproductive organs in the rivers in which 

 it spawns. 



