174 ADULT HERKINGS 



others are still bachelors and spinsters in austere middle age ? 

 When we can answer that question — and the answer is assuredly 

 discoverable — we may be able to claim that we know something 

 about the life-histories of herrings. The writer has more than 

 once heard vain boasts that we know ' all about ' their life- 

 histories, and these were made sometimes by people who should 

 have known better. 



Grovih 



Mrs. Cowan has calculated from the scales the length which 

 each of the 6,848 fish attained at the end of each year of its 

 growth. The results are tabulated in detail. Two examples 

 only can here be given. One sample was landed at Stornoway 

 on the 22nd July 1919 ; 86 fish were examined. In their first 

 year the smallest had grown to 2-3 inches, the largest to just 

 under 6 inches. But no less than 65 of the fish were from 4 to 

 5 J inches long, and 24 were 5 inches. 



Two days later 173 fish were landed for examination at North 

 Shields ; of these 127 were from 2 J to 4 inches long, and 95 were 

 3 to 3J inches, while only seven were 5 inches long. At Peter- 

 head and Wick most of the fish caught in the same month had 

 grown in their first year 3 to 4 inches ; at Scarborough they 

 were 2J to 3 inches. 



At this point the writer would state a problem. Suppose two 

 herrings, A and B, to be hatched in the same brood in October. 

 By the following October, when the first winter ring appears 

 on their scales, A is 3 inches long, B 5 inches. The big fish will, 

 of course, have bigger scales than the smaller one. But suppose 

 them each to survive to their fifth winter ; remove their scales ; 

 and compare them with the scales of two herring (X and Y) 

 known to have been hatched in the February before the birth 

 of A and B. Will the scales of A and B be of a type different to 

 the general type of those of X and Y ? Will they, in fact, have 

 a relatively larger centre than the scales of the spring herrings ? 

 Obviously the unknown quantity is not the actual size of the 

 scales inside the first winter ring, but the proportion of the 

 centre to the whole scale in the third, fourth, and subsequent 

 years. The writer makes no attempt to solve the problem. The 

 scales of spring herrings either exhibit a different type to those 

 of autumn herrings or they do not. In the former case Hjort 

 is correct in saying that spring-spawned and autumn-spawned 

 herring can be distinguished from each other all through life. 

 In the latter case Storrow is right in refusing to differentiate 

 between them. Both theories cannot be right. It is for marine 

 science to decide between them. 



