€f the Fishery Board for Scotland. 



70 



proportion of head length are to be found in the herrings of both seasons, 

 although the percentage of long heads is rather greater in winter than in 

 summer. Here again, then, if we do not consider the slight difference in 

 total length found between the winter and summer herrings sufficient to 

 indicate a distinct variety, neither is there stronger evidence from the 

 length of head. 







TABLE (VI.) showing Percentage o] 

 arranged according to ! 



Sexually Mature Herrings, 

 iead Length. 











•127 



•139 



•151 



•163 



•175 



•186 











to body '. 







ength.... 



{ 



to 

 •138 



to 

 •150 



to 



•162 



to 



•174 



to 



•186 



to 



•198 







&c 



03 



Jan., Feb., March 

 1884 and 1885.. 





3^6 



153 



38-2 



«. 



50-2 



10-2 



2-5 









M 



D 



July, Ai 

 1885 . , 



ig., Sept. 



1 



1^5 



22-3 



50^0 



S 



J4-0 



1-8 



•3 









































TABLI 



J (VII.) showing Percentage of Immature Herrings, 

 arranged according to Head Length. 





Ratio of head length \ 

 to body length.... 1 



•147 



to 



•150 



•151 



to 



•162 





•1 



t 

 •1 



33 



0 



74 





•175 

 to 



•186 



•187 



to 

 •202 



.a 



s 



Jan., Feb., 

 1884 and 



March \ 

 L 1885.. j 





18-0 





34^0 





35-0 



10^4 



!= 

 a 



a 





J 



uly, Aug., Sept. ) 

 188.5 ( 



6^5 



13^0 





61-3 





16-0 



3^2 



















Note. — The variation scale is here for comparison divided, as in Table VI. 

 the 1st division is therefore small, the scale among immatures not passing 

 below •147. 



In Table VII. we find a much larger percentage of what may be called 

 the long-headed herrings among the winter than we do among the summer 

 immature fish, which is in accordance with what has just been stated; for 

 if we turn to the statement (p. 75) of the body lengths of the immature 

 fish, from which Table VII. is compiled, we see that the immatures 

 received during winter were considerably smaller than those of the summer 

 season ; and as the length of head among immatures (at least to a much 

 less size than those we are here discussing) is in inverse ratio to their 

 length of body, we expect to find the winter-season examples — the 

 majority being smaller fish — with the relatively longer heads. 



This circumstance — that the immature fish received in winter were 

 smaller than those of summer — may appear to indicate that the fish of 

 the two seasons were of one and the same hatching, the small winter im- 

 matures having grown some 30 mm. in length, and forming the larger 

 immature fish of summer. Whether this be so or not must be left to be 

 decided by the Examination of the combined characters. The differeiice 

 in length is not so valuable as it might otherwise be, from the circumstance 

 :that about half of the winter immatures were procured by specially small 

 meshed nets. 



The question of locality only now remains to be considered, and the 

 result of an examination for that purpose is given in the following 

 table : — 



