90 



HELEN DEAN KING 



teenth to the twenty-fifth generations, living for the mast part 

 under the handicap of inadequate nutrition, were considerably 

 heavier at all ages than the males in a stock series that were 

 reared simultaneously with them, as a comparison of graph B 

 with graph D in figure 7 shows. The space between these 

 graphs, at the 200-day period, indicates a difference of about 

 17 per cent in favor of the males of the inbred group. 



Growth graphs for various groups of female rats are shown 

 in figure 8. 



Fig. 8 Graphs showing the increase in the weight of the body with age for 

 females belonging to four series (data and lettering as in table 7). 



The growth graphs for various groups of females, shown in 

 figure 8, have the same relative positions as have the graphs 

 for the corresponding groups of males (fig. 7), but they lie some- 

 what closer together. Inbred females of the seventh to the 

 fifteenth generations, as graph A shows, were heavier at all ages 

 (except thirteen days) than the females of the other groups; 

 in the adult state their average body weights were about 2 per 

 cent greater than those of the inbred females belonging in subse- 

 quent generations (graph B). Body weight increase with age 



