EFFECTS OF INBREEDING ON BODY WEIGHT 



17 



TABLE 8 



Shoioing the average body weights at different ages of inbred rats of the A series 

 separated into three groups according to the generation to which the individuals 

 belonged 



* One record only. 



in table 8. In this, as in some of the other figures, the space 

 between the graphs was slightly widened, where properly the 

 lines would run very close together or overlap, in order that the 

 course of each graph might be clearly followed. 



Figure 2 shows that the body growth of the males in the three 

 generation groups of the A series of inbreds progressed at about 

 the same average rate until the animals were 150 days of age, 

 as is indicated by the position of graphs A to C. At this point 

 there was a marked acceleration in the growth of the males 

 belonging to the group comprising the seventh to the ninth 

 generation (graph A) which continued until the end of the weigh- 

 ing period. Graph D, representing the growth of the males of 

 the A series during the first six generations, begins at the 120- 

 day period, as no younger rats belonging to these generation^ 

 were weighed. It seems almost incredible that this graph can 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 26, NO. 1 



