BREEDING SYSTEMS 249 
tions of weak birds may be used, and this will speedily ruin all 
past and future results. Line breeding is one of the best systems 
for improvement if understood and correctly managed. ‘The 
chart (Fig. 126) will enable the poultryman to understand the 
system, so that he may proceed in safety and get sure results. 
LMALE LINE ‘ FEMALE LINE 
C7CTALIONS 
LINE BREEDING CHART ; Ist 
and 
ee0.--- + 
Ge 
Fia. 126.—Line-breeding chart. In this chart the black and white circles and seg- 
ments represent the blood lines, black standing for the male line and white for the female 
line. The solid black lines represent that a male has been chosen from the group from which 
they start and the dotted lines that a female has been chosen. The cross-lined circle at 
the left shows what takes place when out-crossing or the bringing in of new blood lines is 
practised. (After I. K. Felch.) 
Out-crossing, as generally practised, is the use of a male bird 
of unrelated blood with females of the same breed which have 
been in-bred or line-bred for a number of generations. It does 
not mean the introduction of blood of a different breed, but of 
