CANADA PORCUPINE 25 



unconscious reflex glandular activity. While the latter may 

 test the senses more accurately it does not seem proper to use 

 it as a criterion of the learning process. The two cases stand 

 apart on the ground of the voluntary and involuntary features 

 of the reaction. The writer is not aware that any experiments 

 have been made with animals that are comparable with those 

 just described with the porcupines. The problem has been 

 carefully worked and nearly 30,000 individual records have 

 been considered in the foregoing discussion. 



If one would rank animals on the basis of manual dexterity 

 it would count for far more if they should pick up articles with 

 the hands and perform acts such as grasping and carrying food 

 to the mouth. This is a regular habit with the primates and 

 was noted frequently by Cole (10) and Davis (14) in the rac- 

 coon. It is not the natural habit of the porcupine to use his 

 hands in this way unless the food is out of reach, or is so placed 

 that it can be reached with the mouth with difficulty. Food is 

 first grasped and raised with the teeth and then held and manip- 

 ulated with the hands. In the experiments just described, in- 

 volving the use of the hands, food was readily transferred to 

 the mouth when it was placed in the hands. But even after 

 such a habit had been well formed the animals fed in their 

 natural manner off the ground, seizing food first with the teeth. 

 An attempt was made with Nos. 8 and 9 to determine the rate 

 with which these animals could be induced to make use of the 

 hands instead of the mouth in lifting food. No. 8 had shown 

 very remarkable adaptation in the other tests and here she fell 

 into the habit very readily. A piece of food was reached to her 

 on a stick and she very quickly grasped it and took it off. After 

 some practice in this the food was fastened to the stick and held 

 on the box in front of her. If she undertook to take the food 

 with her mouth the food was removed. This was continued 

 until she took it regularly with the hand. The food was then 

 laid in front of her without the stick but was brushed away 

 if she attempted to lift it with her mouth. This was continued 

 until no precaution needed to be taken. The food was then 

 given to her in bulk and she reached for it regularly with her 

 hand. Later it was noted that in gathering scattered fragments 

 from over the cage she picked them up in a very unporcupine 

 manner and had, at least temporarily, lost the tendency to 



