Vol. 6, 1920 
GENETICS: R. PEARL 
227 
It is obviously impossible to present here anything like the total results 
of this extensive piece of work. As a sample of the sort of results obtained 
table 1 is shown. This gives the net average change in butter fat produc- 
tion of daughters as compared with dams. The first column of table 1 
gives the place occupied by the bull in the series of bulls. The second 
column gives the name of the bull. The third column states how many 
MfiW. n/Lf( PRODLfCr/O/i 
nooo 
/asoo 
toooo 
ssoo 
9000 
esoo 
0000 
7SOO 
7000 
esoo 
eooo 
ssoo 
THtX, 
9tT/i 
•:ai r 
; 
554/^ 
1:3 J 9 a:3 e:S -3:3 3 3 4.3 4:0 -5.3 S.3 ^.3 6.9 7.3 7:9 e.3 a o a.3 9.S /0:3 //:3 IJ. Q /z:3 
A6t coMMt/ict/^tnr TtsT 
Fig. 1. Observational and theoretical curves of mean milk production (365 day) at 
various ages in Jersey cows. 
pairs of daughter-dam tests the bull under discussion had. The fourth 
column gives the number of pounds of butter-fat that the bull's daughters 
are in excess or defect of their dams. It is by this column that the bulls 
are arranged, the bull whose daughters produced the most butter-fat 
over the butter-fat production of their dams coming at the top of the list. 
The plus sign shows the daughters produced more butter-fat than their 
dams, the minus sign that they produced less butter-fat. 
