52 HARRY MILES JOHNSON 



apparent that in using animals for operations to settle questions 

 of cerebral localization, it is necessary to use methods of train- 

 ing far more complicated than many physiologists appear to 

 appreciate. Certainly the remarkable variation in the findings 

 of the investigators whose work has been considered in the 

 foregoing pages, may be readily explained by reference to their 

 methods of training. 



APPENDIX I 



On page 5 the reader was referred to a daily record made 

 by one of my animals on pitch-discrimination which is repro- 

 duced below. 



Problem G, Dog 3, December 14, 1911 

 Trial Proper choice Actual choice 



1 R R 



2 L L 



3 R R 



4 L L 



5 R R 



6 R L 



7 R, R 



8 L L 



9 R R 



10 L L 



11 L R 



12 R L 



13 R R 



14 L L 



15 R R 



Correct reactions 12 



Incorrect reactions 3 



Total 15 



Percentage of accuracy SO 



Even superficial inspection will show that this animal was 

 merely choosing the right and the left food-compartments alter- 

 nately regardless of the stimulus given. She developed much 

 more elaborate position-habits than this. This record is shown 

 merely to call attention to the necessity of having se^'eral con- 

 secutive perfect daily records, with the order of presentation 

 and secondaiy criteria under control, before assuming that the 

 animal has learned to discriminate. 



