484 



H. M. JOHNSON 



the "longer" pathways. The expressions "short" and "long" 

 do not refer to geometric distances, but to the relative degree to 

 which the paths retard the propagation of the impulse over them. 

 (Cf. the roughly analogous expression "optical distance.") 12 



17 tS 30 35 40 45 



25 30 3S 40 'is' 



45 



50 



40 



FIG. 6. PERCENTAGE DISTRIBUTION OF REACTION-TIMES OF SUBJECT A 



Ordinates, percentages of reactions. Abscissae, time in units of 0.01 second. 



Graph 13. Light line, 901 left hand reactions under condition B\. 



Graph 13. Heavy line, 900 left hand reactions under condition D\. 



Graph 14. Light line, 901 left hand reactions under condition B\. 



Graph 14. Heavy line, 896 left hand reactions under condition B*. 



Graph 15. Light line, 896 right hand reactions under condition B\. 



Graph 15. Heavy line, 893 right hand reactions under condition D\. 



Graph 16. Light line, 896 right hand reactions under condition B\. 



Graph 16. Heavy line, 890 right hand reactions under condition #2. 



Vertical lines indicate averages. 



12 This paragraph was inspired by oral discussion of the question with Professor 

 Dunlap, but it does not purport to be an accurate presentation of his views. 



