372 The Journal of Heredity 
Crossbre d 
Butter Fat Per Cent. 
70 4 fz 4 ig 
5 6 7 5 9 
Month of Lactation. 
MONTHLY BUTTER-FAT PERCENTAGES 
Graphs showing the monthly butterfat percentages of six crossbred cows and their parents. The 
solid line ( ) represents the crossbred, the dotted line (...... ) represents the dam, and 
the dot-and-dash line (—-—:—-—) the potential record of the sire. (Fig. 24.) 
