of the Fishery Board for Scotland. 



83 



Tables X. and XII. show this more simply, where the position of the 

 fin is indicated as ' before,' ' on,' and ' behind, the centre of body 

 length.' Tables XL and XIII. show the same with respect to the whole 

 length, including head and tail. 



TABLE (X.) showing percentage of 

 Mature Herrings arranged accord- 

 ing to position of centre of dorsal 

 fin, relatively to centre of body 

 length. 



Relative Position. 



Before 

 Centre. 



On 

 Centre. 



Beliind 

 Centre. 



CO 



Winter 



47-6 



15-8 



36-6 



Peicer 



Summer 



23-2 



6-8 



70-0 



TABLE (XL) showing percentage of 

 Mature Herrings arranged accord- 

 ing to position of centre of dorsal 

 fin, relatively to centre of total 

 length. 



Relative Position. 



Before 

 Centre. 



On 

 Centre. 



Behind 

 Centre. 



Percentage. 



Winter 

 Summer 



31-4 



14-3 



54-3 



21-2 



12-8 



66-0 



TABLE (XII.) showing percentage of 

 Immature Herrings arranged as in 

 Table X. 



Relative Position. 



Before 

 Centre. 



On 

 Centre, 



Behind 

 Centre, 



Percentage. 



Winter 



77-0 



16-4 



6-6 



Summer 



66-6 



3-7 



29-6 



TABLE (XIII.) showing percentage of 

 Immature Herrings arranged as in 

 Table XL 



Relative Position. 



Before 

 Centre. 



On 

 Centre. 



Behind 

 Centre. 



-2 



Winter 



56-0 



18-6 



25-4 



Percer 



Summer 



58-7 



10-3 



31-0 



The small number falling on the centre is of course to be expected, there 

 being included in it only those herrings which show the fin in that 

 particular position, whereas the other divisions include the fish falling 

 under all the other grades of variation, and also, of course, those so near 

 the centre as only to differ from those centrally placed by of the 

 length of body. 



These tables show that a majority of the winter herrings, although not 

 a large one, have the centre of the dorsal tin in front of the centre of the 

 body ; whereas among the summer herring a large percentage have it be- 

 hind the centre. Tables X. and XL cannot well be compared with each 

 other, owing to the difference of dimension of the standard of comparison. 



The length of the caudal fin behind the end of scales, although subject 

 to the usual variations, may be said generally to be shorter than the head, 

 this difference being much more pronounced among the winter fish. Hence 

 we find that where the majority of fish have the dorsal fin behind the 

 centre of the body length, as among those of summer, it may appear rela- 

 tively to the whole length as not quite so far back; and, as a consequence, 

 the percentage of fish with the fin behind the centre, relatively to total 

 length, would be slightly decreased. (I use the word centre here as indi- 

 cating a median position and not as an absolutely fixed point). As 

 regards, however, the arrangement followed in Table XL, there will only 

 be a slight difference from Table X., due to the slightly greater length of 

 the heads over the caudal fins causing the centre of total length to be 

 moved forward. Since among the winter herrings the majority have the 



