84 



HELEN DEAN KING 



The relative position of the graphs in figure 5 shows that during 

 the early growth stages males of the B series of inbreds were 

 shghtly heavier at any given age than were the males of the A 

 series; in the period from 100 to 300 days the advantage in body 

 weight was with the males of the A series; beyond this age males 

 of the B series were again the heavier. In the adult state the 

 space between the graphs represents a difference of only about 



TABLE 9 

 Showing the increase in the weight of the body with age for 117 males and 

 for 180 females belonging in the sixteenth to the twenty- 

 fifth generations of the B series of inbred rats 



2 per cent in the average body weights of the two groups of 

 animals. 



Graphs showing the increase in the weight of the body with 

 age for females of the two inbred series are shown in figure 6. 

 These graphs are based on data given in table 8 and in table 9. 



In figure 6, as in figure 5, the graphs lie very close together 

 throughout their entire course. Females in the B series of in- 

 breds were shghtly heavier animals than those in the A series 



