yolk globules, then follows cubical yolk, occupying nearly the whole ovocyte. The peripherical 

 yolk mass is only traced as single granules in the cubical yolk, in main close to the nucleus (39, 

 ref.). 



Figure 4, Ovary of a Murmansk herring, Nov. 3, 1938, Finmark Bank. Length of fish 

 231 mm., weight 106 gm., age 5+, stage III-IV (the beginning of formation of 

 cubicle yolk), x 79. 



The nucleus is of a somewhat extended shape, situated somewhat eccentrically in tlie cell. 

 Along the periphery are found numerous karyosomes, sometimes close to the membrane of the 

 nucleus, sometimes at some distance. Chromosomes are not present as "lamp-brushes", but 

 numerous granules have appeared. They are intensively stained by Heidenhain, and sometimes 

 concentrically distributed. 



The nature of these granules and their relation to the chromosomes are purely histological 

 questions, and will not be treated here. 



The phase of the ripe ovocyte . Diameter 640-1120 mu, average 892 mu. The nucleus can- 

 not be discerned. As long as the ripe ovocyte remains in the stroma of the ovary, the follicle has 

 the same structure as in the preceding phase . The completely ripe ovocytes leave the follicles and 

 are accumulated In the inner cavity of the ovary. In the Murmansk herring the rif>e ovocytes are 

 characterized by a distinct zone with radiate structure, without a downy surface or an additional 

 membrane, characteristical of vobla, bream, perch, and others. 



The ^^^ole mass of ovocytes is filled with large, transparent lumps of yolk, sometimes 



215 



