EGG PRODUCTION. 



71 



TABLE VI. 



Constants Measuring the Degree of Inheritance in Egg Produc- 

 tion. "200-Bgg" Hens and Their Daughters. Experi- 

 ment of IQ07-1908. 



' Stand d 

 deviation * 



CoeflBcient 



of 

 variation.* 



CoeflScient 



of 

 correlation. 



Variation in winter (Nov. 1 — Mar. 1) egg pro- 

 duction. Mothers unweighted. (Table I).. 



Variation in spring (Mar. 1 — June 1) egg pro- 

 duction. Mothers unweighted. (Table I) . . I 



Variation in winter egg production. Mothers . 

 weighted with their fecundity. (Table III)! 



Variation in spring egg production. Mothers] 

 weighted with their fecundity. (Table IV) 



Variation in total** (Nov. 1 — .July 1) egg pro- 

 duction. Mothers weighted with their fe- 

 cundity. (Table V) 



Variation in winter eg 

 (Table III) 



production. Daughters. 



Variation in spring egg production. Dauohters. 

 (Table IV) 



Variation in total ej 

 (Table V) 



production. Daughters. 



Correlation between mothers and daughters in 

 winter egg production. (Table III) 



14.06±1.20' 

 7.73^.66! 



14.93+. 51! 



I 



8.41±.30i 



12.69±.45 

 16.10+55 

 18.10+. 64 

 26. 38+. 94 



25.20 + 2.29 

 13.07±1.13 

 26.57i.97 

 13.80±.49i 



9.32±.33j 

 101.14±6.44 

 38.66 + 1.54 

 35.43 + 1.41 



Correlation between mothers and daughters in 

 spring egg production. (Table IV) 



Correlation between mothers and daughters in 

 total egg production. (Table V) 



Correlation between the mother's individual 

 winter performance and her daughter's aver- 

 age winter performance 



Correlation between the mother's individual 

 spring performance and her daughter's aver- 

 age spring performance 



-0.068 ±048 

 -FO. 023 ±.050 

 — 0.055±.050 



-0.329±.108 



-f-0.034±.121 



From this table the following points are to be noted : — 

 I. Considering first the correlation coefficients at the bottom 

 of the table it is apparent that they give no evidence of a 

 positive correlation between mother and daughter in respect 



* These constants are measures of variation. The standard deviation 

 measures variation in absolute units (in the present case, eggs), while 

 the coefficient of variation measures it in relative (percentage) units. 

 The larger each of these constants is the greater the variability denoted 

 in the character under consideration. 



** "Total" is here used simply as a convenient verbal label of the whole 

 period covered by the egg records in this experiment. 



