HABIT FORMATION IN THE ALBINO RAT 19 



tance, the average number of trials, and the average absolute 

 time for the group. 



The speed is the average number of centimeters traveled per 

 second throughout the learning process, and is obtained by 

 dividing the total time into the total distance. For the twenty- 

 five day group these averages were : 



Time 



Trials Absolute Total Distance Speed 



30 5.7 sec. 224 min. 271.6 meters 20.1 



The curv^es shown in fig. 3 are based on the figures in col- 

 umns 2, 4 and 6 of table II. Only one rat finished in less than 

 fifteen trials, and this is indicated on the first point of the curve. 

 Three rats finished at between fifteen and twenty trials, one at 

 seventeen and two at eighteen trials each, the average being 

 seventeen as indicated on the curve. Between twent}^ and 

 twenty -five trials three rats finished, at twenty-three, twenty- 

 foiu- and twenty -four trials respectively; the average is twenty- 

 three, and the third point on the curve indicates that three 

 rats finished at twenty-three trials. The same procedure is 

 followed in drawing the time and distance curves except that 

 they are necessarily more condensed. Three rats required 

 approximately four hundred seconds each in which to learn 

 the problem, (numbers 11, 15 and 24), and the first point on the 

 time curve indicates this fact. The fourth point shows that 

 six rats consumed from fifteen thousand to twenty thousand 

 seconds (average for the six, seventeen thousand seconds), in 

 their total number of trials. The fifth point in the distance 

 curve is interpreted to mean that six rats covered between 

 three hundred thousand and three hundred fifty thousand cen- 

 timeters, (average for the six, one hundred seventy thousand), 

 in learning the maze. It might be well to notice at this point 

 that all of the cun.^es appearing in this paper are constructed 

 on this same plan. 



