107 



plaice of each monthly age during the first year of life. So far, 

 however, we have hardly enough data to enable us to do so 

 satisfactorily. 



"^^^^ § ~^ ^ S §" 



I I I I I ' 'I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I 



Hge-Groufi F^^^^BIiZr 



iK = Jbos if/on of /neon 



Fig. 7. 



The Ratio of Males to Females. 



We don't know what is the ratio of males to females in 

 the first year of life, but it is probably one of equality. This 

 is also the case (probably) for any year group up to about III. 

 After that, however, a very curious thing happens ; the males 

 diminish in number relatively to the females. This is shown 

 by the following statement, based on the numbers of mature 

 females and males over 23 cms. in length captured on the 

 Sol way spawning grounds and adjacent regions in the spring 

 of 1921 :— 



Size in cms. ... 24, 25, 26, 27, 28, 29, 30, 31. 32, 33, .34, 35, IW, 37, 38 



Females 0, 0, 1, 0, 2, 2, 2, 8, 5,13,11,10,17,25,11 



Males 51, 55, 64, 51, 51, 65, 51, 48, 45, 43, 46, 44, 37, 30, 22 



Size in cms 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65 



Females 0, 3, 0. 0, 1, 0, 0, 0, 0, 1, 0, 1 



Males 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 



Thus, the females caught are always bigger and older fish 

 than the males. They grow a little faster. The interesting thing 

 is that the males apparently die off at a greater rate than do the 

 females, and this probably represents a general law among the 



