A GUIDE FOR KEEPERS OF POULTRY 233 
lines may be developed, one of which shall contain a pre- 
ponderance of original male blood, one a preponderance 
of original female blood, and the third equal proportions 
of original male and female blood. 
“In the chart let 1 represent the original male and 2 
the original female. Then by crossing 1 and 2 the result 
is group 3, which possesses equal parts of the blood of 1 
and 2. Selecting the best pullet from 3 and mating to 
her sire 1, group 4 is produced, which contains 34 of the 
blood of the original sire and %4 of the blood of the 
original dam. Ina like manner the best cockerel from 3 
mated to his dam (2) produces group 5, which is made 
up of 34 of the blood of the original dam and 14 of the 
original sire. Proceeding in a similar manner by mating 
the original parents to their offspring in the third genera- 
tion, we obtain at groups 6 and 7 offspring which con- 
tain either 7 the blood of the original sire and 1% the 
blood of the original dam, or 7% blood of the original 
dam and % blood of the original sire, as the case may be. 
Thus the blood of the original sire has been practically 
eliminated from the female line, and the blood of the 
original dam from the male line. If the original parents 
were still in breeding condition the blood of each could 
be intensified to 15/16 in the fifth generation. To obtain 
the original cross, however, at any generation after the 
second, it is only necessary to select parents from corre- 
sponding groups on each side of the line. As for instance 
‘a cockerel from group 6 mated to pullets from group 7 
will produce in the fifth generation group 9, which con- 
tains mathematically %4 the blood of the original pair. 
Similar results can be obtained by selecting parents from 
4 and 5, for the fundamental law involved works in the 
same way. 
