104 



Centimetres 



It appears therefore that to the north-west of Ireland there 

 are two shoals of herrings, one having a more rapid growth than 

 the other. 



Only one sample from the Firth of Forth was examined this 

 year. It was taken 10th February, 1921, and is interesting when 

 compared with the sample of 10th March, 1920. 



The sample of 1921 contained a large number under 24 and 

 25 cm., and a smaller number under 28 and 29 cm. 



The sample of 1920 had numbers under 23 and 24 cm, and 

 still larger numbers under 26, 27 and 28 cm. 



The particulars are given below : — 



Centimetres. 



Sample. Date. 21 22 23 24 25 26 27 29 29 30 31 Total. 



Firth of Forth ... 10/3/20 2 11 20 27 17 20 32 30 15 2 1 177 



... 10/2/21 — 14 33 65 50 19 7 18 18 4 



Do. 



229 



This difference will be seen from the following table to be 

 due to the large number of fish with four winter rings in the 1920 

 sample. Not only were fish of their age more numerous in the 

 sample of 1920, but they had made a much larger growth than those 

 of the same age in the sample of this year. 



