of the fishery Board for Scotland. 



305 



Meyer, as we have seen, came to the conclusion that the herring at the 

 end of about six months reached a length of approximately 70mm. to 80mm.; 

 at the end of the first complete year a length of 130mm. to 140mm., and at 

 the end of the second complete year, when he supposed iz to attain to 

 maturity, a length of 160mm. to 170mm. 



The amount of growth in length in the first year was thus 130mm. to 

 140mm. (5i- 5| inches), while in the second, and, be it noted, before sexual 

 maturity, it was only 30mm. (1 fa inches). In other words, about 82 

 per cent, of the growth in the period anterior to sexual maturity is 

 represented as occuring in the first half of the period and only 18 per 

 cent, in the second half, a result totally opposed to what happens with 

 other fishes. 



Jenkins, as we have seen, also working on the herrings of Kiel Bay, 

 by studying their otoliths, reduces somewhat the rapidity of growth 

 as brought out by Meyer. He makes the sizes of the annual 

 groups somewhat less than Meyer, and puts the period of maturity at the 

 third year instead of the second, increasing the size at first maturity by 

 some 3 '0cm. He also gives the annual sizes up to the fifth year, when 

 the herrings are between 9 and 10 inches in length. Thus, taking the 

 average sizes as given by Jenkins, we have the following increments per 

 annum before maturity. 



Year. 



Mean Size. 



Increment. 



Percentage Increase on 

 Total Length at Maturity. 







Mm. 



Mm. 





1, 





117 



117 



60-3 



o 





160 



43 



22-2 



3, 





194 



34 



17-5 



Again, if we consider the growth each year as related to the total 

 growth in the five years as given by Jenkins, we have the following: — 



Year. 



Mean Length. 



Annual Incre- 

 ment. 



Percentage Increase on 

 Total Length at 5 

 Years of Age. 





Mm. 



Mm. 





1, 



117 



117 



48-5 



•> 



160 



43 



17-8 



3, 



194 



34 



14-1 



4, 



221 



27 



11 2 



5. 



241 



20 



8-3 



Thus, according to these results, the herring grows in its first year 

 (though not sexually mature till its third year) almost half of the total 

 length it attains at the end of its fifth year. 



The conclusion, I think, is obvious, that both Meyer and Jenkins have 

 jumped at least a year, and that the herring at 135mm. or 117mm. is 

 much more than one year old. 



We are now tolerably well acquainted with the growth of several 

 species of fish, and in all of them the growth in each year anterior to the 

 occurrence of sexual maturity is fairly comparable in extent ; very often 

 theamount of growth in the first year is somewhat greater than in the 

 others, and it diminishes slightly with each successive year; though 

 observers do not always agree about this. 



