OLFACTORY IDENTIFICATION OF CHEMICAL UNITS 



343 



the pattern of alternation of meals with and without amphetamine is the 

 same, but with the mixture unchanged and constant, and in the final choice 

 the same food (with any further addition of amphetamine as in the other 

 groups) is offered in the two cups. 



Fig. 2. Group T : Olfactory discrimination. Each point represents the average 

 of two meals on two days in succession (during the conditioning period). 



12 

 9 

 6 

 3 

 



^^^^>>^ 



Z5 



4,3 



Fig. 3. Group II : Tactile discrimination. 



