168 THE PRACTICAL FISHERMAN. 



Wondrous have been the stories told of the salmon leaps. The old 

 idea was, of course, that when a fish foresaw a difficulty in reaching 

 the upper water of a cataract, it curved itself like a bow, and placing 

 its tail in its mouth, hurled itself as a spring thus bent held between 

 the finger and thumb propels itself through the air. And this not once, 

 but many times in succession, until its object was attained. Of course 

 the idea is untenable, for the question would naturally arise, How does the 

 fish get into position, taking into consideration the tumultuous water 

 from which it springs ? 



To this self put question, I may answer by quoting the capital 

 explanation of the whole modus, which I may here observe is as 

 applicable to a Thames trout, a pike, or a barbel in their occasional 

 leaps, as to the salmon in full vigour seeking to surmount some miniature 

 cataract or weir. Speaking in 1850, Ephemera says: "Last year I 

 paid particular attention to their points, and saw that salmon surmount- 

 ing obstacles in their way as they ascended rivers sprang straight forwards 

 head foremost out of the water, which, with accompanying muscular 

 effort, sent them upwards and forwards. If a salmon means to sink to 

 the bottom it strikes its fins, particularly the dorsal one against the 

 water above. The action of the fins against the resistance offered by the 

 volume of water above tends to force the fish downwards ; on the 

 contrary, when the fins are strongly pressed against the volume of water 

 beneath the fish, the tendency of the pressure will be to propel the fish 

 in a vertical direction, or upwards. The class of fish denominated 

 cetacea, which require to rise frequently to the surface of the water for 

 the purposes of respiration, have tails lying horizontally with the water, 

 and not perpendicularly in it. This nice proviso in nature is to enable 

 them to rise and sink with greater facility. They have only to strike 

 their flat tails against the waters in the depth of ocean, and straightway 

 they are sent many fathoms upwards ; a contrary caudal action will 

 send them down into the deeps again. If the whale were not provided 

 with the flat or horizontal tail, it would die of suffocation, as it would 

 then be unable to lift into vital air his huge carcase from the dark 

 unfathomed caves, in which he cannot long rest for want of ventilation. 

 The dorsal, pectoral, and ventral fins of a salmon are the agents by 

 which they rise and sink in the water. By the agency in great part of 

 the caudal fin or tail they are enabled to propel themselves in any 

 horizontal direction." 



A salmon cannot spring far out of the water, unless it be deep ; but I 

 do not think it need be very deep. In making its spring, it first sinks 

 rapidly by an upward action of the fins, and then suddenly reversing 

 their action and finding a point d'appui in the volume of water under it, 



