274 



HARRIS, KIRKPATRICK, BLAKESLEE, WARNER AND CARD 



and the correlations of the variables in the two populations are essentially 

 identical. 



Because of the uniformity of care and the wide origin of the birds exhib 

 ited each year at the INTERNATIONAL EGG-LAYING CONTEST at Storrs 

 the average productions do not differ widely in the different years. Thus 

 the monthly and annual averages and standard deviations for the 1840 

 birds upon which the equations were based and the 415 birds upon which 

 they were tested appear in table I. 2 



While certain of the differences are significant in comparison with their 

 probable errors it is quite clear that the averages for the two periods are 

 in fair agreement. 



Bird 997, Pen 100 



The method followed in the calculations may be illustrated by one o 

 the calculation blanks for the individual bird No. 997, pen 100. Th 

 first column shows the production for the month indicated by the letter 

 on the stub. This serves as the basis of prediction. The second colum 

 shows the predicted number of eggs for the year, the third shows th 

 deviation of this predicted number from the annual total of 161 egg; 

 The fourth column gives the squares of these deviations of prediction froi 

 observation. The fifth column shows the number of eggs in the remainin 

 months of the year. 3 The sixth column shows the number of eggs predicte 



2 The percentage differences have been calculated by using the monthly averages for 19 

 to 1917 as a base. 



3 The yields for the remaining months (columns 5 to 8) are dropped one space so as to coi 

 cide with the first month of the period. For example, bird 997 laid 161 eggs in the period fro 

 December to October; 161 in the period from January to October; 158 in the period from Fe 

 ruary to October, and so on. 



