CANADA PORCUPINE 15 



EXPERIMENTAL DATA 



Manual Dexterity. — In the process of feeding and taming the 

 animals when they were first captured the problem of right- 

 handedness and lefthandedness presented itself as a study of 

 unexplored possibility. Kinnaman (26) found his monkeys 

 giving preference to one hand over the other, particularly in 

 certain acts, and inferred that this was due to the fact that 

 monkeys stood relatively high in the scale of development. 

 Davis (14) thought he found the same tendency in his raccoons 

 and uses the same assumption, based also on Burke's theory of 

 development in children and Fere's theory of degeneration in 

 imbeciles, for arguing that the raccoon is above the average in 

 the scale of intelligence. Cole (10) failed to report any tendency 

 of his raccoons to use one hand in preference to the other. None 

 of these experimenters, however, made any tests. At this point 

 no attempt will be made to rank the porcupines; but a few 

 results of tests on the procupine's use of his hands will be pre- 

 sented. In all cases except that of No. 4, which will be explained 

 later, tests were made immediately after capturing the animals, 

 before any manual predispositions were brought about by cage 

 environment. The animal in the natural state is free to use his 

 hands in pulling down branches since he can support himself 

 on a perpendicular trunk of a small tree, with his hind feet and 

 tail, using the bristles on the bottom of the latter as a clutch. 

 The forearms and body are then free to be extended in 

 various directions, even directly away from the support. 



Porcupines Nos. 3 to 16 inclusive, excepting No. 11, were 

 used in these tests. No. 11 was not used for the reason that 

 he had but one hind leg and it was feared that this fact had 

 thrown the forearms out of symmetry. A detailed account of 

 the reactions of No. 3 will be given and the others presented 

 in groups as checks upon his results. For the tests, the animal 

 was induced to mount a box about eight inches high, and to 

 stand, or to sit tripod fashion on his hind feet and tail near the 

 edge of the box so that nothing could interfere with the free 

 use of his hands. This is a very natural position for the porcu- 

 pines and is, therefore, no distraction. It soon became a regular 

 habit with No. 3 to mount the box at feeding time so that the 

 task of getting him placed for the test was not disturbing. The 

 experimenter would then take a position in front of the animal 



