REPRODUCTION IN DOMESTIC FOWL 



107 



This case shows the enormous difference which the physical 

 construction of the ovary may make in the number of visible 

 oocytes in exceptional cases. Since this condition has been seen 

 but this once in many hundreds of fowl ovaries examined, it 

 cannot be considered in any way to invalidate the counts of normal 

 ovaries (in the sense of visibility of oocytes) given in table 1 . 



With the data before us, we may proceed to their biometrical 

 analysis along certain lines. 



TABLE 2 

 Constants deduced from table 1 



BREED OR SPECIES 



White Leghorn fowls 



Fi Cross-bred fowls 



Barred Plymouth Rock fowls 



All fowls counted 



Toulouse geese 



Pekin ducks , 



All domestic water-fowl counted 



Guinea-hens 



Crows 



Kingbirds 



. All wild birds counted 



All wild birds and guinea-hens . . 



BREED AND SPECIES COMPARISONS 



The first point for consideration is the relation of the number of 

 visible oocytes to laying capacity in the different breeds. It is 

 evident enough from simple inspection of table 1 that there is 

 no correlation among individual fowls between visible oocytes 

 and egg production. The case may, however, be different when 

 the comparison is made between breeds. As a necessary 

 preliminary to the discussion of this point, table 2 is presented, 

 containing the required biometric constants. 



