reorganization of the gonads, stages II -III and III (0.930). 



The bulk of the Murmansk herring spawns in March and April along the coast of northern 

 Norway. In May and June, the gonads are in stages VI-II and II. A new cycle of maturation starts 

 in July, with the transition from stage II to III. Such is the scheme for most of the large adult 

 herring. With this background, the catch of 14 herrings in stage IV near Spitsbergen in June and 

 July is of a certain interest. 



Marti, leading a cruise with another vessel in the same area at the same time, also found 

 a few herring in stage IV. 



Very often only a part of the total catch was investigated. It is assumed that only an incon- 

 siderable part of the individuals with the sexual products well developed (stage IV) appears in the 

 catches, and tliat such herring may be more frequent in this area. 



All the 14 gonads were investigated very thoroughly. Externally, they could not be distin- 

 guished from the gonads of the bidk of the herring (Figures 14 and 15). Neither was the histological 

 structure of any essential difference (Figure 16). The total physiological development had evident- 

 ly proceeded normally, and, accordingly, the gonads had developed to stage IV at a normal rate. 

 It is therefore assmned that in the autumn an inconsiderable, nearly abortive, spawning of large 

 herring takes place near Spitsbergen. 



Figure 15. Milt of a Murmansk herring, July 2, 1947, western Spitsbergen. Length of fish 

 305 mm., age 8+. Filling of stomach 1, fat 1 . Length of body cavity 166 mm., 

 of milt 147 mm. (88% of the body cavity), weight of milt 40.5 gm. , index of ma- 

 turity 10.5. Stage IV, 2/3 natural size. 



250 



