of the Fishery Board for Scotland. 



47 



Imm. dev.— 19 cm. : eggs, 25 mm. : o, 2 5 mm. : fat, large quantity. 



W. Spr.— 17 to 31 cm. : eggs, -3-'9 mm. : o, 4-28 mm. : t 8-20 mm. ; 

 fat, a large quantity, none. 



Aut. Spr.— 23 to 32 cm. : eggs, 1-0-1-2 mm. : o, 16-31 mm. : t, 21-40 

 mm. : fat, some, none. 



S. Spt.— 21 to 26 cm.: eggs, -12, -15, -25 mm.: o, 3-6 mm.: t, 2-6 

 mm. : fat, large quantity, some. 



The herrings obtained in this month show two well-marked divisions, 

 viz., (1) Immature herrings from 12-21 cm. in length; and (2) winter 

 spawners, 17 to 32 cm. in length. The winter spawners show a long 

 range of development from eggs -3 mm. in diameter to those 1*2 mm. in 

 diameter. The herrings having eggs 1*0 mm. and over in diameter, and 

 those having testes 20 mm. and over in breadth, have been detached from 

 the winter spawners and labelled autumn spawners, as they will probably 

 spawn soon. At the lower end of the winter spawning group there are 

 the herrings that are ripening for the first time ; they have just left the 

 immature group. The immature developing herrings are represented by 

 one fish 19 cm. in length, having eggs -25 mm. in diameter. The 

 immatures had eggs up to "17 mm., which may indicate the beginning of 

 ripening. 



The group of Winter Spawning herrings got at Largs is probably wholly 

 composed of fishes that are ripening for the first time. The upper limit 

 of this lot is 24 cm. The sample gives 17 to 24 cm. as the range in 

 November of the first spawning group of the winter spawners. These 

 limits probably do not give the full range in size. It is noticeable how 

 small the ovaries are in this group of developing winter spawners, in 

 comparison with the size of the eggs. In the following list is given, opposite 

 the length of the fish, the breadth of the ovary in mm., and after each 

 breadth, within brackets, is added the size of the yolked eggs in mm. : — 



Length of 

 Fish. 



cm. 

 17 

 19 

 20 

 21 

 22 

 23 

 24 



5 (-4) 



4 (-3), 6 (-4), 8 (-5) 



5 (-4), 6 (-4), 8 (-4), 8 (-5), 10 (-7) 

 5 (-4), 6 (-5), 8 (-4), 9 (-6), 10 (-8) 

 8 (-5), 9 (-6), 12 (-7) 



10 (-6), 10 (-7) 



15 (-8) 



Autumn and Winter Spawners. — There was a considerable proportion of 

 autumn spawners both among the Clyde and Loch Fyne fishes. The 

 herrings got at Yarmouth during this month were autumn and winter 

 spawners well advanced in the development of the reproductive organs. 



The abdominal fat of many of the winter spawners is being rapidly 

 used up. 



A developing winter spawner had a testis 16 mm. wide. A white 

 powder was washed out, leaving a spongy tissue. The skin of the testis 

 was thin. 



Summer Spents. — A female 26 cm. long had a soft, skin-like ovary, 

 6 mm. in width. The stroma was soft, ductile. There was some spacing 

 between the eggs, the largest of which measured -12 inm. in diameter. 

 Two male spents, 22 and 23 cm. long respectively, had wide vasa deferentia 

 and wide blood vessels. On washing a piece of the testis, which was 2 mm. 

 wide, in water, a shreddy honeycomb structure was observed. Both the 



