ovaries. A section of an ovary in the same stage from Greenland Sea herring (southern part of the 

 Spitsbergen banl() shows quite a different picture. In addition to the complex of ovocytes character- 

 istic of stage III, numerous empty follicles are seen, proving that the herring has spavmed earlier. 

 (Figure I,b, and Figure 11). 



Figure 11. Ovary from Murmansk herring Sept. 15, 1939, caught 70 miles west of North 

 Cape. Length of fish 235 mm., weight 117 gm. Membrane of an ovary with 

 an empty follicle . x 267 . 



It was not unexpected for us to find spent herring near western Spitsbergen in spring and 

 early summer. By the opening of herring on board the vessel, indications of a recently finished 

 spawning (roe purple -colored, containing much blood) were seen in a large number of individuals. 

 Having spawned along the Norwegian coast, large herring (7-13 years, 30-35 cm.) migrate to 

 Spitsbergen waters to feed. 



The presence of empty follicles in Murmansk herring of various age groups indicates 

 the herring spawn each year. 



that 



In herring of stage III empty follicles are present beside the ripening ovocytes, indicating 

 a new cycle in the sexual development. From this we may conclude that: (1) the theory maintained 

 by various scientists, i.e. Frantz (84) that all the reserves of the organism are mobilized to ful- 

 fill one stage in the development of the gonads, and then completely pass over to be used in the next 

 stage, does not hold good. This has been shown above in examples from the Murmansk herring. 



In adult herring, the ripening process of the gonads (i.e., the transition from stage II to III) 

 takes place during the same period in which the empty follicles are resorbed. The energy balance 



224 



