BEHAVIOR OF VERTEBRATES 429 



animals he used three fox terriers and two cats. The arrange- 

 ment of the food boxes, the mode of release of the animals from 

 the cage, the method of giving the stimulus, are all carefully 

 described in the paper. He endeavored to direct the animals 

 to their food by means of sound. They failed within the limits 

 of the experiment to form the association but did develop defi- 

 nite individual habits of response. In the second part of the 

 research he changed to olfaction as a stimulus with the same 

 animals. The experiment was so arranged as to make use of 

 the habits which the animals had set up in the previous work 

 and to strengthen them. Then the mode of procedure was so 

 altered as to compel a modification or change of these habits. 

 He says in discussing this part of the work that if an animal 

 is put in a position where the stimulus is of no particular interest 

 it reacts to this stimulus not directly but with an ordered series 

 of movements. He concludes that his animals were of two 

 types — some more predominantly visual, others kinaesthetic- 

 motor. His experiments were ingenious, his curves and tables 

 are interesting and his discussion is illuminating. 



Sackett's work (48) with porcupines, at the Clark University 

 experiment station, was carried on in the summer out of doors, 

 and in the winter in a large unheated room connected with dark 

 dens and an outside runway. There was a strong effort in all 

 of the work to approximate. the natural conditions of the animals 

 as far as possible. There were 16 animals in all used in the 

 experimentation . 



The paper begins with an interesting account of the natural 

 life of the animal in all phases of its activities. 



The first problem undertaken was one connected with right 

 and left-handedness. The results show that porcupines have 

 very little tendency to be either right or left-handed, but that 

 they can be trained in a few days to take food with a given hand. 

 The theories which try to account for right-handedness are 

 discussed at length. 



The next task set the animals was to take carrots with one 

 hand and cabbage with the other. After a training covering 

 5,000 tests, no. 3 reached for cabbage with his right hand no 

 matter when, where, or by whom it was offered. In an interval 

 of 100 days there was little loss of ability. Other animals were 

 used and developed equal skill. 



