EFFECTS OF INBREEDING ON BODY WEIGHT 



87- 



the inbred rats, both males and females, were much heavier 

 than the stock rats at every age for which records were taken. 

 Not only were the animals in this stock series very inferior in 

 size to those in the first stock series reared in 1913 to 1915 as 

 controls for the inbred strain (King, '15; table 3), but their 

 average body weights during adult life were no greater than those 

 of the rats in the first six generations of the inbred strain which 

 suffered severely from malnutrition (King, '18; table 3). 



Showing the increase in the weight of the body with age for 296 males and 



for 310 females belonging in the sixteenth to the twenty-fifth 



generations of the inbred rats {Series A and B combined) 



To facilitate a comparison between the body growth of inbred 

 rats belonging in various generation groups and that of outbred 

 stock Albinos, graphs showing the weight increase with age in 

 two groups of inbred rats and in two groups of stock rats are 

 given in figure 7 and in figure 8. 



Growth graphs for various series of male rats are shown in 

 figure 7. 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 29, NO. 



