COMPARISON OP OVARIES 



nuclei." In B. cognatus and /)'. n>. woodhous'ii neither the "vitelline bodies" 

 nor the "yolk nuclei" appeared in the long-stored material, and the only traces 

 of the beginning of yolk synthesis was seen in the form of slight cytoplasmic 

 vacuolization, a condition more obvious in B. w. woodhomii than in B. 

 cognatus. 



King suggested that the process of yolk formation is possibly t]uite dif- 

 ferent in various genera and species, and a comparison of the evidences avail- 

 able in Bujo lentiginosus, B. cognatus, B. w. tvoodhous'ii, and Brachydanio 

 rerio would certainly indicate this to be true at least so far as the finer features 

 of the yolk development are concerned. 



From this study of B. cognatus and B. w. woodhous'ii it may be said 

 that yolk formation is associated with nucleolar function. 



In the observations of the ovaries of B. cognatus and B. w. woodhous'ii, 

 the state of the fat bodies was noted in each case. In both species their size 

 during the breeding period was found to be extremely variable. The condi- 

 tion of these structures, therefore, gave no additional clue as to the duration 

 of the breeding period. Apparently, if the size of the fat body is to be used 

 as an indicator in this relationship, other factors such as a variable food sup- 

 ply will have to be carefully controlled. Attempts to locate Bidder's organ 

 in both B. cognatus and B. w. woodhousii were unsuccessful. 



Summary 



The ovaries of ninety-one mature females of Bujo cognatus Say and 

 ninety-nine mature females of Bujo woodhousii woodhousii Girard collected 

 during the known breeding periods were studied volumetrically, macro- 

 scopically, and microscopically in an efifort to determine the nature of the 

 changes which occur in the ovaries during primary oocyte growth, and to 

 see if there is any correlation between the conditions found and the known 

 breeding habits of each. 



The studies reveal that: 



1 . The general structural features of the mature ovaries of B. cognatus 

 and B. w. woodhous'ii are those typical for many related species and genera. 



2. Nucleolar behavior in these species very probably is related to yolk 

 synthesis; though the first formed deutoplasmic material may be organized 

 in situ or originate from sources not demonstratable here. 



3. Volumetrically, macroscopically, and microscopically, the ovaries of 

 B. cognatus appear about equally prepared for ovulation in the months of 

 March through August; while in September there is a gradual waning in 

 this preparation. 



4. The ovaries of B. w. woodhousii are not equally ready for ovulation 

 during the known breeding period, but instead they exhibit a variation of 

 preparedness from animal to animal in the months of March through August 

 with a general decrease in ovulation potential definitely seen in October. 



