83 

 11.— SIZE. 



BY DOROTHY COWAN. 



In previous reports an analysis of the size of the herriiigs 

 examined, together with the size for age, has been given. The 

 data for the year 1919 to June, 1920, will be found in Tables I. 

 and II. The size is expressed to the nearest centimetre, 20-6 to 

 21-5 being taken as 21 cm. 



The samples are indicated by letters for the various ports, 

 and are in the same order as on page 10. 



Table I. shows that the northern samples consisted of much 

 larger herrings than those from the more southerly fishing grounds. 

 This difference remains when herrings of the same age are com- 

 pared, and points to the oceanic herrings from the northern fishing 

 gronnds having a much more rapid growth than those caught 

 in the North Sea. The following table of herrings with three 

 winter rings illustrates the difference in size for the herrings from 

 summer feeding shoals : — 



CENTIMETRES. 



Between summer feeding shoals and autumn spaxMiing shoals 

 there is a considerable difference, the latter having a much larger 

 size for age. Below is given the size for herrings with three winter 

 rings from the summer feeding shoals (F) and autumn spawning 

 shoals (S) of the same port : — 



