76 



TFX'HNICAL BULLETIX 7 



possihlj- be more pronounced in the broody population. Tlie actual correla- 

 tion lietween the presence of broodiness and winter production above the mean 

 is shown by tlie following table: — 



Winter Production 



Xumber above ]K)]ndation mean 



Number below population mean 

 Totals 



Broodv 



561 



534 



1095 



Non-Broodv 



561 



563 



1124 



Coefficient of correlation -[- .02^)4 zr .0143 



The above coefficient is so small as to l)e of no significance and it is less 

 than three times the magnitude of its proi)able error. The deduction must be 

 made from this study that broodiness and winter egg production are entirely 

 independent even though broody birds do lay at a slightly higher rate in 

 winter when they are laying. 



So. Correlation JJeficeen the Presence of Broo/line-ss (unl Winier Production 

 above the Mean of Broodies and Non-broodies combined — Pullet Year (Un- 

 improved Flock 1916). 



Winter Production 



Number abo\e population mean 

 Number below population mean 

 Totals 



Broo'dv 



149 



140 



289 



Non-Broodv 



14 



29 



43 



Coefficient of correlation ^ .3759 = .0318 



The above constant shows that broodiness bears a rather intimate correla- 

 tion to high winter production in the 1916 flock. Such an assumption is based 

 on the conclusion that the individuals laying more eggs in winter than the 

 average of the flock (46.87 eggs) are high producers. Even thougli a small per- 

 centage of the 1916 flock reduced this winter record by being liroody before 

 March first, broody birds appeared to carry intensity to a sufficient extent to 

 enable them to lay more eggs for the ])eriod than did the non-broody birds. 

 It is rather striking that the total population (section 24) should not exhibit 

 a constant similar to that for the 1916 flock. No doubt changes in early ma- 

 turity and winter pause have operated to modify winter production to a 

 greater extent than any possible lowering of intensity by the elimination of 

 broodiness has been responsible for. 



