THE FORMATION OF HABITS AT HIGH SPEED 171 



As the objective records are at variance, it seems at first sight arbi- 

 trary to fix on either one or the other, and to say this is a meas- 

 ure of the truth. 



Series C and D are from animals naturally well fitted to cope 

 with the problem presented; natural fitness, however, varies, and 

 some individuals inaugurate an overpowering set of altogether 

 irrelevant, interfering movements. Such animals, practically, are 

 not competing. Between these extremes most of the other indi- 

 viduals take their places, for their irrelevancies are not sufficient 

 to destroy all chances of success, though marked enough to affect 

 the general averages. The problem is to get out of the tank as 

 quickly as possible, and is solved both by the animal that reduces 

 the complexity of its path, either with or without an increase of 

 speed, and by the animal that compensates inferiority in one direc- 

 tion by superiority in another. The latter might even win, but 

 if we were offering prizes, justice would demand one for improve- 

 ment in speed, the other for improvement in form. As form in 

 the end makes for speed, not in individual cases, but on the 

 average, the time records may be adopted officially as a practical, 

 thougn not necessarily complete, measure of fitness. 



SPECIFIC RESULTS 

 ADULT RATS 



The first experiments were made with a tank differing slightly 

 in size from the one described, and the animals, instead of being 

 dropped into the water through a shoot that landed them in 

 the exact center, were thrown in from one side, with a slight whirl- 

 ing movement. There was but one corner opening through 

 which escape might be effected. The problem was thus essen- 

 tially the same as the one described, and the differences in the 

 records are mainly due to differences in the sizes of the two tanks, 

 and to the way in which the animals were introduced. The 

 whirling movement was adopted in order to insure that the effort 

 to escape might not be begun in any except a chance direction. 

 The results are tabulated below in self-explanatory form. 



