Scientific Investigations. 11 



lierijng is in the majority of instances placed further forward than 

 hi the suniiuer-fish." 



Position of Dorsal Fin. — " It appears that, as the herring grows, 

 the centre of the length of the body comes forward, or, in other words, 

 there is a greater increase in length between the centre of the dorsal 

 fin and the liead than between that point and the tail. It does not 

 seem possible to find any special law regulating the position of the 

 dorsal fin among tlie summer-herrings so far as locality is concerned." 



Position of the Anal Fin. — " In finding the position of the first 

 anal ray we are ascertaining the position of the anus. The circum- 

 stance that the anal fin holds as a general rule a more backward 

 position on the summer-herring than it does among those of winter 

 fairly entitles us, I think, to look upon the suggestion of the difference 

 in relative position of the dorsal fin being distinctive of the fish of 

 these seasons as substantiated." 



Length of the Dorsal and Anal Fins. — " Tlie average of the absolute 

 length of both dorsal and anal fins was greater among the winter- 

 tlian among the summer-herrings, — a circumstance possibly due 

 only to the rather larger size of the winter-fish." 



Number of Rays in the Dorsal and Anal Fins. — Matthews' " observa- 

 tions of the number of rays in the fins, so far as they went, gave no 

 indication of any special distinction in this respect between the 

 herrings of winter and summer. There seems to be a slight tendency 

 towards an increase in the number of rays (always excepting those 

 of the pelvic and caudal fins) as the herring grows larger. The 

 number of rays in the dorsal and anal fins does not seem to much 

 affect their basal lengths." 



Keeled Scales. — Matthews' " observations did not so far enable 

 him to detect such a difference between the respective numbers of 

 the keeled scales as Heincke has done in the Baltic herring, and 

 which enables him to quote them as of racial distinction." 



Sexual Differences. — " No difference in regard to the size of the 

 head, size of the fish, etc., was discovered between the male and 

 female herrings." 



Variation in Size of the Ripe Ova. — " The ripe ova showed an 

 increase in their average size corresponding to increase in the size 

 of the fish. It seemed " to Matthews " that the variable size both 

 of the spawning-herring as well as of their ova probably has a con- 

 siderable effect on the ultimate size of their progeny, but one can 

 scarcely institute a special case of variety on these grounds alone 

 if the smaller fish have every other characteristic in common with 

 the larger herring. The ova of one herring is almost certain to be 

 fertilised by several males." 



" Without a more critical examination than has yet been made 

 it would be unwise to speak definitely on the question of variety 

 among the herrings of our coasts. The only evidence as yet found 

 from the present investigation in favour of such a distinction between 

 the summer- and winter-herrings consists in the more posterior position 

 of the dorsal, pelvic, and anal fins, the undoubtedly smaller head, 

 and the slightly lesser size of the summer-herrings." 



" While suggesting, therefore, that there is a certain distinction 

 between our summer- and winter-herrings," Matthews was " in- 

 disposed to consider the matter as conclusively proved \vithout the 

 c 



