INBREEDING EXPERIMENTS 



107 



shown in Fig. 25. This graph is constructed from data 

 collected from the records of males of line A, but graphs 

 constructed from the records of the females of this line 

 and from males and females of line B do not differ from 



Grow th in bo<^y wci 

 H S«ries A 



ighl Albtno Rat 

 Males 



PTn 



120 140 160 180 200 220 240 260 260 



Age in days 





Fig. 25. — Graphs showing the increase in the body weight with^age for males of inbred 

 albino rats. (Series A.) A, graph for the males of the seventh to the ninth generati< r.u 

 inclusive; B, graph for the males of the tenth to the twelfth generatinns inclusive; C, graph 

 for the males of the thirteenth to the fifteenth generations iucluhive; D, giaph for the n.ult* 

 of the Grst six inbred generations. (After King.) 



it in any essential feature. Curve D is further evidence 

 for concluding that the animals of the first six generations 

 suffered from malnutrition, since, as Miss King notes, it 

 is preposterous to suppose that these animals could have 

 given rise to the very large individuals represented by 



