EFFECTS OF INBREEDING AND CROSSBEEEDING. 



25 



1906 /906 1910 /9I2 /9/4 /9/6 19/6 1920 

 200 



180 

 /60 

 /40 



\ fOO 



^ 80 



60 



:=z3:z::^ 



B 



40 



20 







Fig. 6.— The average gain between birth and 33 days. Inbreds {A ) and controls (£), 1906 to 1920. Cor- 

 rected for eflect of size of Utter as in Figure 1. 



/906 /906 /S/0 /9/2 /S/4 /9/6 /S/6 /S20 

 230 



260 

 240 

 220 

 200 

 /SO 

 ^ /60 

 ^ /40 



"^ ,20 



/oo 



80 

 60 

 40 

 20 

 O 



\ 



»— -^ 7 



—^ ^^'^.^ \ t »^ 



\ * ' 



\ — % ^ ^ 



B 



Fig. 7.— The average weight at 33 days. I nbreds {A ) and controls (5 ), 1906 to 1920. Corrected for effect 



ofsizeoflitterasin Figure 1, 

 106851°— 22— Bull. 1090 4 



