^30 Journal of Comparative Neurology and Psychology. 



presentation, and not from the nature of his materials. He constantly annoys his 

 reader by making statements which rest upon facts that are presented further on 

 in the discussion. This tends to weaken the work, for it makes the reader feel that 

 after all the book is too largely an attempt to verify surmises. 



Whether Bose's researches are to prove to be important contributions to general 

 physiology further investigation should soon decide. At present they should 

 serve the excellent purposes of stimulating interest in the reactions of plants, and 

 of emphasizing the fact that the range of vital responses is far larger than is usually 

 supposed. If the author's books are accepted immediately as authoritative state- 

 ments of fact, general physiology may lose more than it gains by them. I am confi- 

 dent that there are few experimentalists in biology who might not profit by the 

 study of Bose's method of investigation; and it is to be hoped that his books may 

 stir other investigators to attempts to test the truth of his statements. 



R. M. Y. 



Watson, John B. Kinesthetic and Organic Sensations: Their Role in the Reactions of the White 

 Rat to the Maze. Psychol. Rev., Monogr. SuppL, vol. 8, no. 2, May, 1907, 100 pp. 



Dr. Watson's study is an attempt to apply what he calls an "adaptation of an 

 established method to meet new conditions." The established method is the 

 method of extirpating a sense-organ; the new conditions are those involved in the 

 study of the effect of such extirpation upon the learning processes of animals. 

 Briefly, the experiments investigated the consequences of removing the eyes, the 

 middle ears, the olfactory bulbs or the vibrissae of white rats, or of making their 

 paws anaesthetic, upon their reactions to the Hampton Court maze. As a pre- 

 liminary to the tests upon operated rats, it was found that rats which had learned 

 the maze in the light could go through it in darkness without error, that untrained 

 rats could learn the maze as readily in the dark as in the light and that emphasizing 

 the tactual and kinaesthetic sensations by making the rats squeeze through holes in 

 wooden blocks at "the entrance to the true pathway at every point where the maze 

 offers a choice of turns" rather delayed than facilitated the learning process. One 

 rat, indeed, made a complete failure of the darkness tests. When the maze was 

 equipped with miniature electric lights so placed as to illuminate the proper open- 

 ings, this rat did well when the lights were turned on, but could not learn the maze 

 in the dark. Rather than to suppose that he was guided by brightness discrimina- 

 tion, the author prefers to adopt a suggestion of Professor Angell's, that the clue 

 was the eye muscle pull established by the tendency to look at the light. 



Rats with the eyes removed showed no disturbance in traversing the maze which 

 they had already learned in the normal condition. Nor did untrained rats, similarly 

 operated on, have any difficulty in learning the maze. Rats with the olfactory 

 lobes removed and those with the middle ear removed were likewise normal in 

 their behavior to the maze. Removal of the vibrissce did disturb the first few per- 

 formances of rats that had previously learned the maze when normal, but rats 

 without vibriss:e learned it for the first time without difficulty — a curious fact to 

 which we shall refer later. No effect upon either trained or untrained rats was 

 observed from making the paws or the nose anaesthetic. The theory that the rat 

 utilizes "the possible differences in the temperature values to be found at the correct 

 turns versus the incorrect" it was attempted to test by placing at a certain point 

 in the maze a copper plate, which was in some experiments cooled to the freezing 



