ANNUAL MOLT AND EGG PRODUCTION 85 



7. Total days broody in the pullet year was independent of length of 

 molt period. 



8. Persistency showed a significant correlation of — .3613 with duration 

 of molt. 



9. Weight at first egg exhibited no relationship to duration of molt. 



10. Gain in body weight during the pullet laying year was independent 

 of molt duration. 



11. Egg production previous to the molt showed a negative correlation of 

 .3695 with length of molt, which is statistically valuable. 



12. The number of eggs laid in 365 days by the pullet gave a negative 

 correlation to molt duration of .3592, which may be considered significant. 



13. Vigor did not affect duration of molt. 



14. Second-year egg production was negatively correlated with length of 

 molt to the extent of — .2960, which is probably significant. 



15. All significant correlations occurred where the regression was non- 

 linear. 



16. In general, highly intense layers and persistent layers exhibited the 

 shortest molt period. This fact indicates that the physiological process of 

 molting and feather growth took place at a more rapid rate in heavy layers. 



References 



Blakeman, J. 1905. On tests of linearity of regression in frequency distri- 

 bution. Biometrika 4:332-350. 



EzEKiEL, M. 1929. Meaning and significance of correlation coefficients. 

 Amer. Econ. Rev. 19:246-250. 



Hays, F. A. and Ruby Sanborn. 1926. Annual persistency in relation to 

 winter and annual egg production. Mass. Agr. Expt. Sta. Tech. Bui. 9. 



Hays, F. A. and Ruby Sanborn. 1927 a. Intensity or rate of laying in re- 

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



Hays, F. A. and Ruby Sanborn, 1927 b. Net correlation of characters con- 

 cerned in fecundity. Mass. Agr. Expt. Sta. Tech. Bui. 12. 



Hays, F. A. 1927. The inheritance of persistency and its relation to fecund- 

 ity. Proc. World's Poultry Congress, pp. 92-95. 



Hays, F.A. and Ruby Sanborn. 1928. Vigor in production-bred flocks. 

 Mass. Agr. Expt. Sta. Bui. 242. 



Hays, F. A. and Ruby Sanborn. 1929. Rate of growth in Rhode Island 

 Reds. Mass. Agr. Expt. Sta. Bui. 2.59. 



Pearson, K. 1905. Mathematical contributions to the theory of evolution 

 XIV. Cambridge University Press. 



Pearson, K. 1924. Tables for statisticians and biometricians. Second edition, 

 p. XXXII. Camibridge University Press. 



Slutsky, E. 1913. 'On the criterion of goodness of fit of the regression lines 

 and on the best method of fitting theni to data. Jour. Roy. Statis. 

 Soc. 77:78-84. 



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AND FiNANCS 



3M-6-'30. No. 9485. 



