EFFECTS OF INBREEDING ON BODY WEIGHT 



11 



A comparison of the corresponding data for the individuals of 

 the two series of inbreds is best made through the graphs in fig- 

 ure 1 constructed from the data for the average body weights at 

 different ages as given in table 1 and in table 2. 



In figure 1 the graphs for the body growth of the males are 

 considerably higher than those for the females, since the male 

 rat, after reaching maturity, is normally a much heavier animal 

 than the female of like age. Considering that only one record 



Fig. 1 Graphs showing the increase in the weight of the body with age for 

 males and females belonging in the first six generations of the two series of 

 inbred rats (data in table 1 and in table 2). • 



was taken for each animal the corresponding graphs for the two 

 series, especially those for the females, run remarkably close 

 together. It is evident, therefore, that there was no significant 

 difference between the two series as regards the growth of the 

 individuals during the first six generations of inbreeding. 



Table 3 gives the -body weight data for all of the individuals 

 of the first six inbred generations for which records were taken 

 (a combination of the data in table 1 and in table 2). 



