characterized as belonging to a transitional stage . 



\.*- 



»>^ 



Figure 9. Ovary from Murmansk herring April 4, 1939. a, fish 241 mm., 87 gm., age 6+, 

 stage V, X 67; b, fish 226 mm., 70 gm., 6+, stage VI. The empty foUicles and 

 the whole complex of ovocytes found in stage II are visible . 



Stage in is especially characterized by a large number of vacuoles in the protoplasm . The 

 site of these vacuoles can be given schematically as follows: comparatively few vacuoles with the 

 yolk intensively colored are found in one layer; larger, light-colored vacuoles in two layers, along 

 the periphery, and surrounding the nucleus. From this we can conclude that the vacuoles are of a 

 double character: they may originate from the epithelium, either distributed at the periphery, or 

 around the nucleus. In Figure 10, drop-like vacuoles are seen close to the nucleus, as if pushed 

 out from it. When the vacuoles fill aU the protoplasm, the picture is characteristic of a typical 

 stage ni. 



For the sake of simplicity we do not divide stage IE into sub-stages, as such features are 

 seen in histological sections only. 



The Determination of the Maturity Stages of the Ovary from 

 the Number of Ovocytes in Histological Segtions 



TTie number of ovocytes in the various phases of development, per square unit of histolog- 

 ical section, may serve as an additional criterion for the objective judgement of the stage of matu- 

 rity of an ovary. In order to verify this assumption, some calculations have been made. The 

 method has been described previously. The results are shown in Table 4. 



221 



