no 



EAYMOND PEAEL AND WILLIAM FREEMAN SCHOPPE 



tions. Apparently what happens in the ovary of the fowl after 

 the bird reaches laying age is that ova are constantly migrating 

 to the surface and developing thereon up to something under 1 

 mm. in diameter. Of these a much smaller number continue 



TABLE 3 

 Mean number of visible oocytes in Barred Plymouth Rocks of different ages 



2400 



JZ Id Z4 30 



MEAN AGE. IN MONTHS 



Fig. 2 Showing the change in mean number of visible oocytes with advancing 

 age in Barred Plymouth Rocks. 



their growth and are finally laid. Since the number developing 

 up to the 1-mm. size, however, always greatly exceeds in any 

 given time unit the number developing farther to laying size, and 

 since this disproportion may be reasonably assumed to become 

 progressively greater as laying activity diminishes, which it is 



