188 THE SALMON RIVERS OF SCOTLAND 



transform the fall into a huge surging rapid with force enough 

 to wash every fish out of the pool below, and to send white 

 superaerated water away down through the Otter's Hole to the 

 neck of the Little Crooked. When the winter conditions of 

 water temperature have yielded to the advance of summer, 

 the Garry fish succeed in making the ascent. They are still 

 shapely athletic fellows, well suited for the undoubted effort ; 

 yet it is more the question of temperature than the nature of 

 the obstacle which causes them to delay till May before making 

 the attempt. A less serious obstacle would check their ascent 

 in the same way. Garry fish are frequently much marked by 

 old wounds having healed up, and while the seals of Inverness 

 Firth may no doubt account for many of the marks, I suspect 

 that the rocks of the falls have also much to do with the 

 condition. I have noticed the same in the Moriston fish 

 the few I have had an opportunity of observing. Further, it 

 is believed by those who have much experience in stripping 

 and artificially hatching fish that violent struggles in the 

 overcoming of obstacles have a serious effect upon gravid 

 females in materially reducing the percentage of eggs which 

 will fertilise. 



Summer and autumn runs of fish do not, it is said, penetrate 

 as far as the Garry in this district, and therefore the Garry fish 

 when ascending the falls in question in May and June cannot 

 be called gravid fish markedly open to this danger, but to 

 reduce the difficulties at such places is all in the interests of the 

 fish, and would not influence the total catch of the lower Garry. 



A point of considerable interest in this district is the reason 

 why the Garry, the farthest up river of all, should be the place 

 where the best spring fishing is obtainable. What attraction 

 is there in the Garry to make it a spring river ? This question 

 has repeatedly been asked. 



With the object of obtaining some definite information on 

 this point I arranged in the winter of 1901-1902 that a series 

 of maximum and minimum temperatures should be taken both 

 in the Garry and in the Ness from instruments kept constantly 

 immersed and read daily at stated intervals. From the 

 readings thus obtained I calculated the weekly means and 

 plotted the results on a chart which is reproduced on page 174. 



The flat and relatively high curve representing the Ness will 



