26S MANTON COPELAND 



when the external nares are covered is really due to the lack of 

 stimulation of the oral receptors, or perhaps to an insufficient 

 stimulation cf them, for, as already stated, a certain amount 

 of water unquestionably is taken into the mouth when the 

 nares are sealed. 



In order to determine conclusively which interpretation of 

 results was the correct one it became necessary to sever the 

 olfactory nerves, an operation accomplished with little diffi- 

 culty. A small opening was made in the. roof of the cranium 

 above each nerve, a fine pointed scalpel was inserted, and the 

 cuts made. Notes made on the behavior of a newt with its 

 peripheral olfactory apparatus rendered inoperative in this man- 

 ner are as follows. Before the operation, which was performed 

 at 10 A. M. on July 24, it snapped at meat, filter paper and 

 meat juice. 10:13 A. M. — The animal showed no ill effects from 

 the operation whatsoever. It followed and snapped at meat, 

 and pursued a ball of filter paper rolled over the sand, a char- 

 acteristic response of the normal individual. Meat juice, how- 

 ever, induced no reaction in five trials. A piece of meat was 

 then immediately seized and swallowed. 10 130 A. M. — Meat was 

 pursued and snapped at as before, but in five trials with meat 

 juice no reaction appeared. It then followed meat moved 

 through the sand, when the juice again brought forth no re- 

 sponse in five trials. 11:15 A. M. — By squirting a mixture of 

 carmine and water over the olfactory apertures it was clearly 

 demonstrated that the operation had in no way interfered with 

 the normal flow of water through the nasal chambers and the 

 mouth. July 25, 8:30 A. M. — The newt followed a wad of 

 filter paper in characteristic manner. 9 150 A. M. — Several tests 

 were made with meat juice without response. A piece of meat 

 was actively followed before, between and after the tests with 

 beef juice. 3 .'50 P. M. — A bag filled with cheese cloth was 

 nosed as normally. Then one containing meat was substituted 

 for the first, and the animal induced to approach by moving 

 it. It was nosed for many seconds and then deserted. (Another 

 animal with functioning olfactory organs nosed the same bag 

 and snapped at it actively.) A roll of filter paper was imme- 

 diately pursued and seized, when it was taken away and the ani- 

 mal fed with meat. 



The behavior of two other individuals whose olfactory nerves 



