No. 599] 



ADVANCED REGISTRY COWS 



677 



of record, pounds of milk, pounds of fat, and per cent, of 

 fat were all tabulated. Each animal was given an arbi- 

 trary number which denoted its position in the genera- 

 tion, and the position of all its direct ancestors in their 

 respective generations back to the primary ancestor of 

 the population. All advanced registry males were tabu- 

 lated also and numbered. 



Eecoeds Obtained 

 From the female, Aaggie Grace, No. 2618, H.H.B., only 

 456 advanced registry records were obtained in 10 genera- 

 tions. In order to secure these records about twice as 

 many animals were tabulated, the others consisting of 

 the A.E.O. sires and their daughters that had not them 

 selves made A.E.O. records but had two or more A.E.O 

 daughters. 



The male, Paul De Kol, No. 14634, H.F.H.B., in 9 gen- 

 erations produced 9,639 female progeny with A.E.O. 

 records. About twice this number of animals were tabu- 

 lated to secure these records. 



Tabulation of Data 

 Necessarily, before this large accumulation of data 

 could be studied systematically, it was necessary to tabu- 

 late it in concise form, and for this purpose correlation 

 tables were made for each population, each table involv- 

 ing a pair of variables. Thus age was compared to 

 pounds of milk, age to pounds of fat, and age to percent- 

 age of fat ; three tables to each population. From these 

 tables the means of the characters in classes, class aver- 

 age deviations, population means, average and standard 

 deviations and correlation coefficients were worked out. 

 Then from these data, curves were drawn to illustrate 

 its trend graphically. 



Eesults 



The correlation tables I and IT, compiled for the pur- 

 pose of studying the frequencies and distributions »! the 

 population originating in the male, Paul De Kol, are not 



