272 MANTON COPELAND 



absolute refusal of these animals to eat, after severance of the 

 olfactory nerves, seems to show that the olfactory sense is the 

 one mainly used by Diemyctylus in recognizing food.". 



The behavior of these animals does not justify, to my mind, 

 the author's conclusion. The nearly complete disappearance of 

 the following reaction, and "the absolute refusal of these ani- 

 mals to eat" seems to show little else than a general physiologi- 

 cal disturbance following the operations. Of the three newts, 

 whose olfactory nerves I severed, one followed and snapped at 

 meat in a few minutes after the operation, and the other two 

 did the same on the day succeeding. Such reactions only showed 

 that the animals after the operations were behaving in respect 

 to a moving object as they had before, thus giving evidence 

 that they were, in general, physiologically normal, and accord- 

 ingly in suitable condition for experimental study by the methods 

 already described. Judging from the behavior of my animals, 

 it seems certain, therefore, that those operated upon by Reese 

 really did give evidence of being "the worse for the operation," 

 and accordingly their failure to respond to juice from meat and 

 earthworms might have been attributed to causes other than 

 non-functioning olfactory organs. My method of operating was 

 quite unlike that of Reese, a fact explaining, in all probability, 

 the differences in behavior described. 



SUMMARY 



i. An inedible object, such as a ball of filter paper, suspended 

 in an aquarium is discovered, approached and nosed by Diemyc- 

 tylus as quickly as a piece of meat. 



2. A cheese cloth bag containing meat is approached, nosed 

 and snapped at, whereas a similar one filled with cheese cloth 

 is approached and nosed but no attempt is made to seize it. 



3. When an extract of raw beef is squirted over the external 

 nares, the newt responds by snapping its jaws or biting at the 

 sand on the bottom of the aquarium where the juice settles. 



4. When the peripheral olfactory apparatus is rendered in- 

 operative, both bags are approached and nosed but neither is 

 seized, and beef extract squirted over the snout excites no 

 reaction. 



5. A moving inedible object may be seized or even swallowed, 

 whereas the same thing stationary is nosed and rejected. 



