ANNUAL PKUSISI'KNC ^' AND KC.C. I'liODlC'TION 



11)1) 



Nmiil>or of birds .... 

 Mean total days broody . 

 Broody standard deviation 

 Mean annual persisteney . 

 Persistency standard deviation 

 Coefficient of correlation . 

 Repression days broody on persistency 

 Regression persistency on days broody 



1037 

 i2.()9 



±27.33 

 294.05 



±64.-82 

 +.0532: 

 +.022 

 +.126 



.020.0 



Intensity of broodiness, as measured In' tiie total days spent in broodiness 

 dtiring the pullet year is subject to wide fluctuations. Its standard deviation 

 .shows marked variability in the population. In view of this fact, it seems 

 probable that intensity of broodiness depends on a number of variables. 



The .small and .statistically insignificant coefficient of correlation indicates 

 practical independence between degree of broodiness and annual persistency. 



12. Correlation Between Annual Persistency Above the Mean and the Pres- 

 ence of Broodiness. 



This section deals with the absolute relation between tlie presence of tiie 

 inherited characteristic, broodiness, and persistency greater than the mean of 

 the population studied. Herein lies a definite basis for selection which may 

 or may not be useful in breeding for high persistency. The following results 

 appear: 



Coefficient of correlation 



—.2081 ±.0139 



The above negative correlation coefficient is statistically significant though 

 it does not reveal an intimate correlation. Eliminating the broody character- 

 istic should in some measure increa.se annual ]»ersislency. 



(C) The Relation Bktwekn Pkuststexcy axd FECuxDiri' 



Since high annual persistency appears to be a desirable cliaracteristic to 

 develop from several standpoints, it is higlily desirable tiiat its relation to 



both winter and annual egg record be ascertained. Both relations may be 

 considered first from the quantitative standpoint and then from tiie qualita- 

 tive standpoint by use of long and short correlation tables, respectively. 



