HABIT FORMATION IN ALBINO RATS 



9 



the case with the normal controls. The relative brain weight 

 (in reference to body length) of the inbreds is 4.43% less than 

 that of the normals. The relative brain weight (in reference 

 to body weight) of the inbreds is 7.99% less than that of the 

 normal control. The percentage of water in brain and cord 

 normally decreases with age ; but in the inbreds used in the maze 

 experiment, although killed, on the average, fourteen days later 

 than the control rats, the percentage of water was greater. 



The figures presented in Table I support the hypothesis that 

 a less than normal average brain weight in a strain of rats is 

 accompanied by an average lesser ability to form habits. 



TABLE la 

 THE MAZE 



DAILY LEARNING AVERAGES OF INBRED AND NORMAL CONTROL RATS 

 (Time in seconds) 



Inbred Average 531 .665 



Control Average 505 . 128 



Inbred Average. , 

 Control Average 



Inbred Average . 

 Control Average . 



Inbred Average . 

 Control Average , 



Inbred Average . . 

 Control Average. 



Inbred Average . , 

 Control Average . 



Inbred Average . . 

 Control Average . 



Inbred Average. 

 Control Average . 



Inbred Average . 

 Control Average , 



