18 



grows faster. The necessary correction has been indicated in 

 fig. 1 by the dotted Hne. The two lines intersect at about the 

 period of the formation of the fourth winter ring, and further 

 work with reference to actual as compared with calculated growth 

 may show that the point of coincidence is relatively constant 

 with respect to size and age. The calculated size is too small 

 previous to this point of coincidence and too large afterwards. 

 It is easy to see that because of this want of correlation between 

 the growth of the scale and the fish the first formed winter rings 

 should present the descending series in size, but it is not so easy 

 to point to any but an empirical method of correction. 



From what has already been said, it is plain that selection takes 

 place, but it is reassuring to find it is not an alarming selection with 

 reference to size that a first view of the facts appeared to indicate. 



The herring is the only species which has been intensively 

 studied in this wa3^ But probabty the principle herein enunciated 

 will be found to be generally true. In all cases we know the scale 

 apjoears late, and the probability is that because of its late appear- 

 ance it grows proportionally faster than the fish. 



Lea refers to Sund's * paper on the sprat and Fage's t paper 

 on the pilchard, in both of which it may be seen that the calculated 

 size at each winter ring is smaller in successive year groups. From 

 Sund's tables it is evident that in the sprat there is similarly a 

 want of exact correlationship between the growth of the scale 

 and the growth of the fish. 



Miss Lee { has discussed the point also with regard to the 

 herring, and found the conditions to be similar in the haddock. 

 The feature is illustrated in this report in the paper by IMr. Storrow 

 on the " Age and Growth of Fish," especially Avith reference to 

 the long rough dab. 



It is equally well illustrated in the many tables which have 

 been pubhshed relating to the herring, and even if the younger 

 calculated sizes be contrasted with the older calculated sizes. 



* 1911. Undersokelser over Brislingen. Aarsberetning Vedkommende JSTorges Fiskerier. 

 t 1913. Recherches sur la biologic de la Sardine. Arcliives de /oologie experimentale 

 et gonerale, tome 51. 



t 1912. Publ. d. circ. No. 63. 



