210 HOW A SALMON LEAPS. 



suddenly snapping the strain by prompt with- 

 drawal of the tail from the mouth, are jerked 

 upwards, like the dog that was sent sprawling into 

 air by the cow with the " crumpled horns." This 

 is merely laughable : but it is singular that Mr. 

 Scrope, a salmon -fisher, according to his own 

 showing, of more than a quarter of a century's 

 experience, should have stated that on an average 

 salmon jump no further in height than six feet, 

 though he conceives that very large fish, in deep 

 water, could leap much higher. Last year I paid 

 particular attention to those points, and saw that 

 salmon surmounting obstacles in their way as 

 they ascended rivers, sprang straight forwards, 

 head foremost out of the water, no doubt, in a 

 great degree, by means of striking their fins against 

 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 resist- 

 ance 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 denomi- 



