12 MASS. EXPERIMENT STATION BULLETIN 443 



3. Intraclass correlations point strongly to the inheritance of clutch size from 

 both sires and dams in all four seasons. This is particularly evident in winter, 

 spring, and summer. 



4. There is no evidence of sex-linked genes controlling clutch size. 



5. Net rate of laying is closely related to mean clutch size in each of the four 

 seasons. 



6. In gross annual rate and gross annual production, mothers and daughters 

 show the same magnitude of correlation. 



7. Mothers and daughters show a significant correlation in both winter and 

 spring production but not in summer and fall production. 



8. The data on the whole substantiate that the mean performance records of 

 families of daughters is the best measure of breeding ability of females. 



REFERENCES 



Dryden, James. 192L Egg-laying characteristics of the hen. Oreg. Agr. Expt 



Sta. Bui. 180. 

 Goodale, H. D. 1918. Internal factors influencing egg production in the Rhode 



Island Red breed of domestic fowl. Amer. Nat. 52:65-94, 209-239, and 301-321. 



Hays, F. A. 1924. Inbreeding the Rhode Island Red fowl with special reference 

 to wanter egg production. Amer. Nat. 58 (654):43-59. 



Hays, F. A. 1944. Relation of intensity to egg weight and egg production. 

 Mass. Agr. Expt. Sta. Bui. 416. 



Hays F. A. 1944a. Factors affecting annual egg production. Mass. Agr. Expt. 

 Sta'. Bui. 423. 



Hays, F. A. 1946. Egg records as a criterion for selecting breeding hens. Poul- 

 try' Sci. 25 (6):622-627. 



Hays, F. A., and Ruby Sanborn. 1927. Intensity or rate of laying in relation 

 to fecundity. Mass. Agr. Expt. Sta. Tech. Bui. 11. 



Hays, F. A., and Ruby Sanborn. 1932. Types of intensity in Rhode Island Reds. 



Mass. Agr. Expt. Sta. Bui. 286. 

 Knox, C. W., M. A. JuU, and J. P. Quinn. 1935. Correlation studies of egg 



production and possible genetic interpretations. Jour. Agr. Res. 50 (7) :537-589. 



Lerner, I. M., and L. W. Taylor. 1936. The relation of pause to rate of egg 



production. Jour. Agr. Res. 52 (l):39-47. 

 Lerner I. M., and L. W. Taylor. 1943. The inheritance of egg production in 



domestic fowl. Amer. Nat. 77:119-132. 

 Snedecor, G. W. 1946. Statistical Methods. Iowa State College Press, Ames, 



Iowa. 

 Tomhave, A. E. 1941. Intensity of fall and winter egg production of pullet 



progeny sired by cockerels sib tested for intensity of production. Del. Agr. 



Expt. Sta. Bui. 232. 



