54 



COIiPAHISON OP RESULTS OBTAINED FOR THE DIPFERKIIT AGES. 



Table VII shows the general averapes for each age as vfell 

 aa those for the males and females sejt-arately. Averages for 

 the 500-flay rats are oni-pted for reasons already given. 



The number of trials required by the rats in order to 

 learn the maze increases with age ei^cept in the case of the 

 300-day grouj, where tlie average is very slightly below that 

 of the 200-day group. 



The 65-day males learned the problem in fewer trials than 

 the 25-day ones but the females of the older group required 

 more trials than those of the younger. There is rather a sharp 

 dividing line between the young animals (25 and 65 da2/s ) and 

 the old animals (200 and 300-days) the former acquiring the 

 maze habit with considerably fewer trials than the latter. 



The total time consumed in perfecting the habit also 

 shows a regular increase with age except for the G5-day rats 

 whose tine record is slightly below that of the 25-day ones. 

 The apparent superiority of the older group over the younger 

 is attributable solely to the record made by the males, sine? 

 the females at 65-day3 have a higher record than those at 25 

 days. Again we see that the two younger groups are quite dis- 

 tinct from the two older ones, requiring considerably less 

 total time in which to learn the problem. The high average of 

 the 300-day group is due in part to the large number of failures 

 which occurred in early trials at that ape, but is alsc partly 

 attributable to their slower bodily movements. 



Total distance shows a regular increase with increasing 



