262 MANTON COPELAND 



pants of the aquarium nearby became alert or active. If, next, 

 a roll of filter paper was substituted for the meat, it, in turn, 

 was followed in the same way, and the response to the inedible 

 object was just as marked when the meat was not introduced 

 at all ; in fact, paper moved along the outer surface of the glass 

 aquarium was watched and followed. 



Finally, an experiment was devised to test reactions to a 

 stationary object, and to show whether meat would be found 

 more quickly than something from which no material capable 

 of producing chemical stimulation could possibly emanate. A 

 piece of raw beef was hooked on to the end of a wire fastened 

 into a wooden bar, which was wedged between the sides of the 

 aquarium above the surface of the water. In this way the meat 

 was held in a fixed position in the water a few millimeters above 

 the bottom of the aquarium, in which were placed five newts. 

 The time elapsing between the introduction of the meat and 

 its discovery by one of the animals was recorded. Care was 

 taken that the animals should not see the meat as it was being 

 placed in position, and thus be attracted by its movement. 

 When the bait was discovered, nosed and snapped at, or seized, 

 it was removed be ore it could be eaten, and in no two consecu- 

 tive trials was it placed in the same position in the aquarium- 

 In five trials, the average time taken to discover the meat was 

 1.8 minutes. Five trials were then made with the substitution 

 of a ball of filter paper for the meat, when the average time 

 taken for its discovery was 3.3 minutes. Upon repeating the 

 experiment, the results were reversed. The average time taken 

 to find the meat was 2.4 minutes, whereas the filter paper was 

 located in 1.2 minutes. In the ten trials, the difference in the 

 average times taken to find meat and filter paper was not more 

 than a few seconds. 



All these tests, and subsequent ones, indicate that the ap- 

 proach to an object, edible or inedible, is a visual reaction, and 

 that, under the conditions described, if smell plays a part in 

 food recognition, it does so after the animal has discovered and 

 moved to the source of the stimulus. 



The seizing reaction. In the reactions to the stationary meat 

 and filter paper one significant difference was noted. Whereas 

 the meat was always nosed and seized, or snapped at, the filter 

 paper, although invariably nosed, was bitten only five times in 



