EFFECTS OF INBREEDING ON BODY WEIGHT 



89 



more vigorously during the adolescent period, but they were 

 not as heavy as the inbred males in adult life. Since the inbred 

 males were fully as large as the males in the stock series that had 

 been reared under much more favorable conditions of environ- 

 ment and of nutrition, it is evident that continued inbreeding 



Fig. 7 Graphs showing the increase in the weight of the body with age for 

 males belonging to four series. A, graph for males of the seventh to the fifteenth 

 generations of the inbred strain (series A, B) ; B, graph for males of the sixteenth 

 to the twenty-fifth generations of the inbred strain (series A, B); C, graph for 

 males of the selected series of stock Albinos reared in 1913 to 1915 as controls 

 for the inbred strain; D, graph for males of the stock series reared simultaneously 

 with the individuals of the twenty-first to the twenty-fifth generations of the 

 inbred strain (data in table 10 and in table 11 of the present paper and in table 

 13 of 'Studies on inbreeding I;' King, '18). 



has not produced a deterioration in the original stock as regards 

 the normal weight increase with age. The males in the seventh 

 to the fifteenth generations of the inbred strain were much su- 

 perior in body weight to outbred stock males reared under simi- 

 lar environmental and nutritive conditions (compare graph A 

 with graph C in figure 7). Likewise, inbred males of the six- 



