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E. C. MACDOWELL AND E. M. VICARI 



SCALEOF RATIOS 



DISTANCE PER DAY 



RATIOS OF TESTS VS CONTROLS 



1.5 



STRAIN C 



2 3 4 



ALL STRAINS 



2 3 4 



DAYS OF TRAINING 



DAYS or RETENTIOM 



Fig. 10 Ratios of the distance averages of tests vs. controls on each day of 

 training and retention. The base line represents equality of the test and control 

 averages; that is, ratios of 1.000; points above the base line represent 'plus' 

 ratios, obtained when the test average was larger and so divided by the control 

 average; points below the base line represent 'minus' ratios, obtained when the 

 control average was larger and so divided by the test average. Accordingly, 

 points above the line show that the tests covered more distance than the controls. 

 'Completes' and 'incompletes' have been used, males and females together; 

 vertical scale gives the size of the ratios; horizontal scale, days; the first series 

 of days gives training; the second series, retention. 



