188 



TECHNICAL BULLETIN 8 



19. Annual intensity shows a considerable degree of negative correlation 

 to length of winter pause. 



20. A very intimate positive cori'elation exists between low annual in- 

 tensity and the presence of winter pause. 



2L Annual persistency is hut slightly positively correlated with length 

 of winter pause. 



22. Birds that pause during winter slu)w a tendency to lay later in the 

 fall than non-pause birds. 



23. The mean size of winter clutches is rather intimately positively cor- 

 related with winter fecimdity. Clutch size is a very good measure of in- 

 tensity. 



21'. Length of winter pause is negatively correlated with winter pro- 

 duction. 



25. Low winter production exhibits a considerable degree of correlation 

 to the presence of winter pause in the total population. 



26. Length of winter pause is negatively correlated with annual egg 

 record in the pause population. 



27. Annual production heh'W the mean is substantially correlated with 

 the presence of winter pause in the total population. 



28. Although winter cycle and winter pause are complements of each 

 other, they are practically independent in duraiion in the pause group. 



29. Winter pause is definitely shown to lie a characteristic detrimental to 

 both winter and annual fecundity, and should tiierefore be eliminated from 

 flocks bred for epg production. 



References 



Davenport, E. 1907. Principles of Breeding, p. 471. Boston, New York, 



etc.: Ginn & Co. 

 Goodale, H. D. 1918. Winter cycle of egg production in the Rhode 



Island Red breed of the domestic fowl. Jour. Agr. Res. XII.: 547-574. 

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



Rhode Island Red breed of the domestic fowl. Amer. Nat. 52:65-94, 



209-232, and 301-321. 

 Goodale, H. D., and Ruby Sanborn. 1922. Changes in egg production in 



the station flock. Mass. Agr. Exp. Sta. Bull. 211. 

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



reference to winter egg production. Amer. Nat. 58:43-59. 

 Hays, F. A., Ruby Sanborn and L. L. James. 1924. Correlation studies 



on winter fecundity. Mass. Agr. Exp. Sta. Bull. 220. 

 Hays, F. A., and Ruby Sanborn. 1926. Broodiness in relation to fecun- 

 dity in the domestic fowl. Mass. Agr. Exp. Sta. Tech. Bull. 7. 

 Hurst, C. C. 1925. Experiments in Genetics. Cambridge: Cambridge 



University Press. 

 Pearl, Raymond. 1912. Tlie mode of inheritance of fecundity in the 



domestic fowl. Papers from Maine Biol. Lab. 37. 



