196 ALBERT M. REESE 



them enough to keep them from snapping at the pipette, but 

 not enough to cause them to withdraw from the jet of sugar 

 solution when squirted against them. 



Experiment 4. This experiment was to test the reaction of 

 Diemyctylus to a bitter solution, and a nearly saturated aqueous 

 solution of quinine sulphate was used. No reaction at all was 

 obtained except when the solution was squirted upon the head. 

 In this case there was sometimes a rather slow withdrawal, but 

 usually the reaction was quite marked, the animal shaking its 

 head in evident discomfort, or with what in the case of man 

 would probably be disgust. 



After reacting negatively to the quinine the animal would 

 usually respond in the ordinary way to meat juice that was 

 offered in the same manner. One animal that paid no attention 

 to meat juice reacted, though not actively, to the quinine solu- 

 tion. 



Picric acid was not tried because, as has been shown by Sheldon, 

 the acidity is apt to cause a more marked reaction than the 

 bitterness. 



Experiment 5. As an example of a neutral saline solution 

 sodium chloride was used. Nine animals were used, and a 4% 

 solution of the salt in distilled water was first employed. This 

 solution when squirted upon the head caused a negative reaction 

 in all of the animals. In two or three the reaction was quick and 

 violent, the animal shaking its head in evident discomfort. In 

 others the reaction was quick but not violent ; and in others the 

 reaction was slow, taking place only after an entire pipette or 

 more of the solution had been used. 



On other parts of the body the 4% solution caused in all but 

 one or possibly two, animals a long-delayed but usually marked 

 negative response. In some animals the response consisted in 

 simply a twitching of the part stimulated, in others there was 

 a slow withdrawal from pipette, while in others the animals bit 

 at the point stimulated ; but even in the animals where the 

 latter response took place, it was usually so slow that one or 

 more entire pipettes of the solution had to be used before the 

 reaction occurred. 



A 2 % solution caused definite responses in all but three of the 

 animals when used upon the head, though the reaction was not 



