EFFECTS OF INBREEDING ON BODY WEIGHT 



79 



shown in figure 2. The data from which these graphs were 

 constructed are given in table 5. 



In general the relative position of the graphs in figure 2 is much 

 the same as that of the graphs in figure 1. Graph A, represent- 

 ing the body weight increase with age for females of the sixteenth 

 to the eighteenth generations, runs higher than any of the other 

 graphs for the greater part of its course, while the position of 

 the other graphs indicates that there was a gradual decrease in 



Showing the average body weights at different ages of inbred rats of the B 



series, separated into groups according to the generation to 



which the individuals belonged 



the body growth of the animals as inbreeding advanced. The 

 females of the twenty-fifth generation (graph D) were, on the 

 whole, sHghtly heavier than were the females of the pi^eceding 

 generation group (graph C). 



Table 6 gives data showing the average body weights at differ- 

 ent age periods of males and of females belonging to various 

 generation groups of the B series of inbreds. 



