of the Fishery Board for Scotland. 



93 



The first series of scales varied in number from 8 to 11, the average being 

 9 "2. The second series varied from 18 to 20, with an average of 18-7, 

 the majority of the fish having 19 scales. The third series varied from 

 13 to 17; the average 14*5. The various numbers represented in each 

 season form several combinations with the others, the commonest being 

 9, 19, 14 = 42; but it seems doubtful whether any racial distinction will 

 be discovered in respect to this characteristic among the Scottish herring. 



Reproductive Organs. 



Besides subjecting to examination the external characteristics of the 

 Scottish herrings, the condition of the reproductive organs was taken note 

 of, both for the purpose of ascertaining the sex of the fish and whether 

 any distinction could be drawn between male and female in other respects, 

 and also whether any light might thereby be thrown on the subject of 

 variability. 



No difference in regard to size of fish, size of head, &c., was discovered 

 between the male and female herring. Both sexes were represented in 

 all the grades of general size, and both showed the same number and 

 extent of variations. Nor was there an appreciable difference in the 

 number of males and females caught ; the percentage in the samples 

 examined (1100) being — of summer fish, 50 '8 per cent, females, 49 '2 per 

 cent, males; of winter fish, 52*5 per cent, males, 47*5 per cent, females, 



A little experience permits of a very fair determination being made by 

 naked eye examination only, of the condition of ripeness of the generative 

 products, as more accurately ascertained by microscopical examination. 



For convenience in classifying the herrings according to their sexual 

 condition, I divided them into the following stages of maturity: — (1) 

 Ripe — that is, either just commenced to spawn or where the appearance 

 and size of the ova, as well as the ease with which it could be expressed 

 (and this cannot be done in the fresh fish without exaggerated pres- 

 sure, unless it is fully ripe), showed that spawning would have taken 

 place almost immediately. (2) Three-quarters ripe, when the ovary 

 filled the whole abdomen completely, but the ova were smaller and 

 not so clear as when fully ripe, and only a few had yet passed into 

 the oviduct, or even into the undivided duct-like portion of the 

 ovary. (3) Half-ripe, where the ovary was fairly large^ but not so 

 large as to appreciably distend the abdomen, in which the ova were 

 visibly smaller and less ripe than in the last stage, and were still firmly 

 adherent to the ovarian septa. (4) Quarter-ripe, where the ovary was 

 small in bulk, only about one-half to three-quarters the length of the 

 abdominal cavity, the ova not half the size of ripe eggs, and solid and 

 opaque-looking in mass. (5) Spent, when the ova were fully extruded, 

 and the ovary presented a slack and partially corrugated appearance ; or 

 quarter, half, three-quarter spent, according to whether the ova had been 

 to that extent extruded before capture. (6) Immature, with small, red, 

 gelatinous-looking ovary, the ova indistinguishable by the naked eye. A 

 similar distinction was made in the case of the male fish, although the 

 absence of the naked-eye evidence of the state of development of the 

 spermatozoa made it rather less certain. Those herrings with the ovary in 

 an earlier stage than that of quarter-ripe, and in which the ova were just 

 visible, and the ovary little larger than that of the wholly immature herring, 

 were included with the more mature fish, for the purpose of defining the 

 extreme characteristics, but were specially marked as probably having 

 reached sexual maturity for the first time; my reasons for coming to which 

 conclusion have already been stated. 



