298 



Appendices to Fifth Annual Report 



the one indicating a position anterior and the other a position posterior to 

 the centre of the area of variation, and form with these the different triple 

 combinations which are possible, we find the result expressed in the fol- 

 lowing table. It seems to give no evidence of special racial distinction, 

 the pectoral fin being, in respect to its position, combined in nearly equal 

 numbers with most of the combinations of dorsal and anal fin positions. 



TABLE XXIII., showing on what percentage of the Mature Herrings 

 various combinations of the relative positions which the Dorsal, Anal, 

 and Pectoral Fins occupy on the Body, are met with. 



Position of Dorsal Fin, 

 Position of Anal Fin, 

 Position of Pectoral Fin, 



Anterior 

 Anterior 

 Anterior 



Anterior 

 Anterior 

 Posterior 



Anterior 

 Posterior 

 Anterior 



Anterior 

 Posterior 

 Posterior 



Posterior 

 Anterior 

 Anterior 



Posterior 

 Anterior 

 Posterior 



Posterior 

 Posterior 

 Anterior 



Posterior 

 Posterior 

 Posterior 



Percentage of Herrings, 

 with the triple com- 

 bination, . 



18-7 



15-5 



13'0 



4-4 



6-1 



187 



8-7 



14'8 



Percentage of Pectoral 

 Fin position to each 

 double combination 

 of Dorsal and Anal 

 Fins, 



54-7 



45-3 



75-0 



25-0 



24-7 



75-3 



37-0 



63-0 



The pectoral fin then gives no support to the supposition that there may 

 be a racial distinction between the various fish in either season. So it is 

 with the other more important characters, as the commonest ground holds 

 in all cases a median position in the whole extent of the variation. Of 

 course the larger proportion of the fish show a combination of these, but in 

 no case is the commonest ground found entirely in combination with the 

 commonest ground of other characters. Thus the extreme conditions of 

 any character are found not to be restricted to fish showing the extremes 

 of any other such, but encroach on the commonest ground of others, or in 

 many cases are even combined with both extremes of one or more others. 



As I have already stated, no distinction sufficient for the determination 

 of more than one race, can be found among the herring of any particular 

 localities, but when we examine them as separated according to the seasons 

 in which they were caught, we do find a small difference in some respects. 

 This was stated for the herring as a whole, irrespective of size, but when 

 we class them according to the length of their bodies as in Tables XXIV. 

 to XXX., we find that the remark holds good for every size. Now if we 

 take the summer and winter fish separately, and class them according to 

 the date of their capture, say each of the three months of both seasons, we 

 do not find that this circumstance holds good. Of course we find the 

 characters varying at these times over the same ground, but the fish pre- 

 senting them are found not to be confined to any one month — not even to 

 show the slight tendency in that direction, which we find between the 

 summer and winter herrings. The variations appear to be indiscriminately 

 present on fish of the same date of catch and in the same shoal. Since 

 the fish with the dorsal fin in its extreme positions are not to be considered 

 separate races, because they are found intimately mixed up together and 

 not presenting such special combinations of characters as to support this 

 assumption, it may be questioned whether the summer and winter fish, 

 both of which fall within the same extremes of variation, are to be con- 

 sidered as such. The circumstance that a similar slight distinction between 

 thelherring of the two seasons is found in respect to the position of the 



