REACTIONS OF THE SPOTTED NEWT 195 



the head from side to side, when a strong solution was em- 

 ployed. If the stimulus were of unusual strength, the animal 

 might roll over and over, as though in great agony, and then 

 dart away to a distant part of the aquarium. Chemicals of 

 this strength were seldom used more than once, because of the 

 possible injurious effect upon the animal. 



A weak stimulus on the hinder parts of the animal usually 

 caused a slow motion forward to escape the stimulus, though 

 occasionally a slight twitching was the only response; the 

 twitching was usually followed, however, by the forward motion 

 if the stimulus were continued. A more violent stimulus of 

 this region caused a sudden start forward, and the animal very 

 frequently reached back and bit at the spot stimulated. A still 

 more violent stimulation produced not only the biting reaction, 

 but caused the animal to roll over in apparent agony as was 

 noted above in connection with the stimulation of the head. 



A remarkable amount of variation was noted in the different 

 animals in regard to their sensitiveness to chemical stimulation, 

 both on the head and on the body regions. A stimulus that 

 would cause one animal to respond in a violent way, as though 

 it caused considerable pain, would have almost no effect upon 

 another animal. The same animal at different times also showed 

 considerable variation in sensitiveness ."owing, it may be supposed, 

 to variations in the physiological condition. It is possible that 

 the variation in sensitiveness may be due partially to variations 

 in the cuticle, though this could not be definitely determined. 

 At any rate, the cuticle is shed with remarkable frequency, and 

 it may be that when it is beginning to loosen preparatory to 

 being cast, it may make the animal less sensitive to stimulation. 



Experiment 3. To test the reaction of the animals to what is 

 to us a sweet taste a ro% solution of cane sugar in distilled 

 water was used. This concentration makes a very sweet solu- 

 tion, in fact almost a syrup, but no reaction proper was obtained 

 by prolonged stimulation of either head or body regions, though 

 all of the animals on hand were tried. That the solution was, 

 however, not entirely without effect seems possible from the 

 fact that while the animals in this experiment frequently snapped 

 at and even seized the empty pipette or one containing pure 

 water, they never acted in this way towards a pipette contain- 

 ing the sugar solution. It would seem that the sugar repelled 



