164 Thivty-ninth Annual Meeting 



in the air and only (jne of these showed two fish jnmpint;-. 

 One optical ihnsion was thus effectively dispelled. 



I was interested to see whether the fish chose any particular 

 point of attack for the leap. As already indicated the fall 

 was considerably lower at one place and the jump necessary 

 to reach solid water above was consequently much shorter. 

 Yet so far as I could tell within the time of my observations, 

 fewer fish tried the fall at that point than at others either 

 right or left of it. I was inclined to believe that the point of 

 attack was determined largely by the depth of the water 

 below the fall. At least the shallowest points were those from 

 which the fish did not jump, and the extreme left of the 

 stream where the water was quietest and certainly very 

 deep was also one of the most frequented jumping places. 

 It was also the place where the fall was most perpendicular 

 and highest. At the same time it must be recorded that some 

 fish were seen jum])ing all along the entire line of the fall 

 and that the preferred point of attack seemed to .shift from 

 one half hour to the next. 



It was difticult to determine the height of the jump made 

 bv the salmon. There was hardl}' a single case in which a 

 fish jumped higher than the crest of the fall and in nine out 

 of ten cases at least the jump was not high enough to reach 

 the crest. The fish dashed frequently right through the sheet 

 of falling water and struck head first against the face of the 

 rock with sut^cient force to stun them so that they were car- 

 ried away disabled, floating down stream some distance 

 before they recovered sufiiciently to start in swimming again. 

 Even when trying at the low point of the fall they often 

 landed on a rock, bounding off against another {)oint only to 

 be carried down by the rush of water. 



The length of the jump was \ery \arial)le, as also the start- 

 ing point of the leap. At times a salmon rose from the water 

 near the face of the fall and again one came from the 

 smoother waters some distance back from this point. In the 

 latter case even a long fine jump resulted only in bringing the 

 fish down head first amony" the rocks at the base of the fall. 



