100 Appendices to Twenty -second Annual Report 



To facilitate comparison, the total Numbers and the Sex Percentages 

 for the two seasons are given : — 







Numbers. 



Percentage. 





Group. 



Length. 



Both Sexes. 



Males. 



Females. 



Remarks. 







1902. 



1903. 



1902. 



1903. 



1902. 



1903. 





1 



26 inches and under. 



75 



119 



23 



29 



77 



71 



Chiefly Females. 



2 



26| to 27 inches, - 



36 



32 



56 



53 



44 



47 



Mixed Sexes. 



3 



27\ to 31£ inches, - 



50 



41 



82 



71 



18 



29 



Chiefly Males. 







161 



192 



48 



42 



52 



58 





4 



32 to 37 inches, 



58 



130 



7 



8 



93 



92 



Chiefly Females. 



5 



37J inches and over, 



25 



39 



76 



85 



24 



15 



Chiefly Males. 







83 



169 



28 



26 



72 



74 







Total, - 



244 



361 



41 



35 



59 



65 





It will be noticed that in the first three groups (which comprise 

 grilse and a few of the smaller salmon), there is not much inequality 

 in the aggregate proportions of males and females. The fourth group 

 almost entirely consists of females, weighing from 12 lbs. up to 23 lbs.; 

 the males being very poorly represented and nearly all 36 inches or 

 over, weighing not less than 18 lbs. 



The data are insufficient, yet suggest the idea that the presence of a 

 large number of males in the fifth group, and their almost total absence 

 in the fourth group, may be due to artificial rather than to natural 

 causes. It is probable that males grow more rapidly than females, as 

 after spawning they quickly descend the river and may be putting on 

 weight in the sea, while the latter are hanging about in fresh water, as 

 many of them have been proved to do. Unfortunately, the " Marking 

 Returns," do not yet supply much information about the rate of growth 

 of males, though they shed light on that of females. As a rule the very 

 heavy fish reported are males, and perhaps owing to many of the older 

 members of this sex appearing after the nets are off, they escape 

 capture for a longer period than the majority of females. 



Still, these habits do not seem to account for the great scarcity of 

 males between 12 lbs. and 22 lbs., and it is possible that the explanation 

 may be that a proportion of each run of grilse in the previous season 

 failed to pass the nets. There are grounds for believing that some of 

 these runs are largely composed of males, which, if spared, would have 

 grown into medium-sized salmon by the autumn of the following year, 

 or returned as larger fish at a later period. 



