Bui. 1090. U. S. Dept. of Agriculture. 



Plate 



Fig. I. — Male of Family 2, Belonging to the Twelfth Generation 

 of Inbreeding. 



Fig. 2. — Female of Family 2, Full Sister of the Male Shown Above. 



This family is characterized by frequent but rather small litters, heavy mortality at birth but 

 great vitality and longevity thereafter. It is second in resistance to tuberculosis. 





