II. SIZE OP THE BODY AND ORGANS 



83 



From this study we conclude, therefore, that captivity for 

 ten generations has reduced the brain weight of the test Grays 

 only by 5 per cent in the males and 3 per cent in the females. 

 The shift is toward the relations characteristic for the Albino, 

 but still leaves some 10 or 11 per cent to go. The data as they 

 stand do not show any marked tendency to a progressive re- 

 duction in brain weight. As to the parts of the brain here 

 examined, these vary as does the remainder of the brain, and 

 hence retain a constant percentage weight. 



G, 



G 2 



65 



C 8 



8 



Abo 



71 londord 



-15 



-20 



Cliart 16 Brain weight : Deviations of limiting values above and below the 

 mean in each generation of captive Grays. Females. 



ON THE WEIGHT OF THE HYPOPHYSIS IN THE CAPTIVE GRAYS 



Standards : Data in reference table 148 for the Albino and 

 data in table 205 for the wild Norway. The hypophysis is 

 lighter in the wild gray Norway than in the Albino. This 

 difference is specially marked in the female hypophysis. 



The deviations in the weight of the hypophysis of the cap- 

 tive Grays from albino standards are given in tables 16, 17, 

 and 18 and chart 17. The course of the graphs for the two 

 sexes is similar. When the base line used for reference 



