HABIT FORMATION AND FEELING QUALITIES 295 



be followed by hesitation and false movements. One subject 

 termed it the " bumpy and rocky" condition. These three 

 hindrances operated with greater or less intensity throughout 

 the middle section, depending largely on the subject and his 

 methods of work. The first hindrance was readily overcome by 

 I, while it continued beyond the limits of the section for J and K. 

 The second class of hindrances was of minor importance to I 

 and K, but proved serious to J. 



Of course the general concave form of the curve calls for no 

 comment as the percentages of improvement were per force 

 lessened with the gradual achievements of higher records. The 

 descriptions here given concern characteristics superimposed 

 upon the general form. 



The second joint or limit of the middle section occurs for the 

 normal subjects at 9, 11 and 12P respectively, and in the com- 

 bined curves (graph 5) for all conditions at the IIP, and marks 

 the beginning of the section of diminishing gains. It should be 

 observed that from this stage on to the end of the practice the 

 margin left for further possible gain is comparatively small. 

 Concerning the normal subjects, I had gained at the 10P 95 per 

 cent, J at the 12P 93 per cent and K at 13P 94 per cent of his 

 total percentage of improvement. Evidently over nine-tenths 

 of their speed capacity is developed when one-half of the prac- 

 tice is completed: it required the remaining one-half to squeeze 

 out the last tenth. But there is still the question, why did the 

 second break appear at all and at these few adjacent periods. 

 Considering the normal subjects only, the immediate cause is 

 found in the relatively small gains in the tenth, twelfth or thir- 

 teenth period according to the subject. The evidence for the 

 indirect causes is largely introspective. I's curve in graph 1 

 shows a very slight break at 9P. This suggested an examination 

 of the record at 10P. It reads: 



"I place emphasis on the aces as a means of orientation in memory, 

 but in actual performance it is just one card after the other with the 

 attention just a little ahead at each movement. The order of the 

 cards, the order of the movements and position of the boxes are now 

 working together and are at ready command," but in IIP this interest- 



