December 7, 191 1] 



NATURE 



173 



I 



The actual text of the work must be passed over 

 with the bare remark that " Rangin " appears to 

 have acquired a considerable knowledge of equine 

 anatomy, both normal and pathological. 



R. L. 



A^^IMAL PSYCHOLOGY. 

 La Nouvelle Psychologie Animale. By G. Bohn. 

 Pp. ii + 2oo. (Paris: F. Alcan, 1911.) Price 2.50 

 francs. 

 Clever Hans {the Horse of Mr. Van Osten) : a Contri- 

 bution to Experimental Animal and Human Psycho- 

 logy. By Oskar Pfungst. With an introduction by 

 Prof. C. Stumpf. Translated from the German by 

 Carl L. Hahn. With a prefatory note by J. R. 

 Angell. Pp. viiJ-274. (New York: H. Holt and 

 Co., 191 1.) Price 1.50 dollars net. 

 T^R. BOHN'S book is, as he himself states in his 

 J^ preface, the sequel and complement of an earlier 

 work, " La Naissance de ITntelligence," already re- 

 viewed in the pages of this journal. Its aim is to 

 present a concise account of the development of 

 psychism in the comparatively high forms of life repre- 

 sented by the class of anthropods and vertebrates 

 respectively. The vital activities of the lower organ- 

 isms are not neglected, however, and in the opening 

 pages of the book one finds an excellent summary of 

 the forms of explanation in terms of physical chemistry 

 which Prof. Loeb has made famous under the names 

 "tropisms" and "differential sensibility." 



Dr. Bohn is Loeb's most distinguished follower, and 

 he has defined the above-mentioned terms and indicated 

 exactly to \\hat forms of behaviour they are applicable 

 with a brilliance even superior to that of the master 

 himself. There is little doubt that the terms have 

 been used with great laxity by many writers, parti- 

 cularly by those psychologists who are inclined to 

 reject Prof. Loeb's views, and Dr. Bohn has done a 

 real service to science in rendering them precise. 

 Moreover, no one unhampered by preconceived theories 

 will find fault, on the score of method, with Dr. Bohn 

 for endeavouring to apply the law of parsimony as 

 rigidly as possible, and only appealing to psychical 

 factors after all the possibilities of physical and 

 chemical explanation have been exhausted. Yet the 

 result may not be entirely convincing, for although 

 the observation of lowly forms of life encourages a 

 mechanical system of explanation which the man of 

 science is then stimulated to develop with ever-increas- 

 ing complexity until it seems to give an approximately 

 accurate account of even the higher forms of conscious 

 behaviour of highly developed organisms, an investi- 

 gator starting from the other end of the scale and 

 acquiring an intimate knowledge of the nature and 

 significance of consciousness in the life of man and the 

 higher animals is likely to come to a very different 

 conclusion as to the nature of, say, even protozoan 

 activity. It seems, indeed, inevitable that there should 

 be at least two widely diverging schools of thought 

 in animal psychology, out of the conflict of the views 

 of which truth will ultimately emerge, and that both 

 are therefore necessary to the science. 



Dr. Bohn passes on to a clear statement of the 

 NO. 2197, VOL. 88] 



meaning and sphere of influence of "associative 

 memory," and after a full discussion of the principal 

 instincts of "articulated" animals, in which he shows 

 that the word "instinct" explains nothing, and that 

 the so-called instincts are aggregates of diverse activi- 

 ties which are far from exhibiting the exact adjustment 

 to one another and to the environment with which 

 they have been hitherto credited, he describes the 

 principal experimental methods employed in the in- 

 vestigation of the psychical activity of the vertebrates, 

 together with the more important results of these 

 investigations. The little book is crammed with the 

 most valuable material, set out in the most concise 

 and attractive style, and one is glad to note that it 

 has been crowned by the Academy of Moral and 

 Political Sciences. No ps3xhologist should omit to 

 read it and re-read it. 



"Clever Hans" was a Russian trotting horse, who 

 took German music-hall audiences by storm bv his 

 remarkable power of working simple arithmetical 

 sums, and answering other questions requiring a 

 similar kind of reasoning ability. The owner, an 

 elementar3--school master, had taken him when young 

 and taught him the rules of arithmetic according to 

 the ordinary approved methods, and was himself 

 convinced of his bona fides. An unofficially appointed 

 Commission of psychological experts eventually proved 

 conclusively, by experiments with the animal, that no 

 true reasoning processes were performed, but that the 

 horse, who tapped out its answers with its right fore- 

 leg, judged, by minimal muscular movements uncon- 

 sciously performed by the questioner, when it had to 

 stop. The questioner in asking the question was 

 found to bend slightly forward, and then unconsciously 

 straighten himself when the correct number of taps 

 had been given. A slouch hat improved the "scores" 

 by magnifying the amplitude of the movements, and 

 when the questioner himself did not know the answer 

 the horse was quite unable to give it. For further 

 details of this most entrancing story, the reader is 

 referred to the book itself. 



WiLLiA.M Brown. 



OUR BOOK SHELF. 



Vine-growing in England. By H. M. Tod. Pp. x + 

 113. (London: Chatto and Windus, 1911.) Price 

 15. net. 

 The vision of the British householder sitting under 

 his own vine seems capable of being realised from 

 the perusal of Mr. Tod's interesting little treatise on 

 vine-growing in England. The author examines the 

 historical evidence connected with the vine in England 

 and points out conclusively that its culture was once 

 widespread not only in the country but also in and 

 around London. Its decline no doubt was largely 

 brought about by the dissolution of the monasteries, 

 and it is also suggested that the enclosure of the land 

 rendered many situations unsuitable for vineyards. 

 The practical details for successful viticulture given in 

 this book are admirable, and the author speaks with 

 authority gained from a wide experience of vine grow- 

 ing in England, Europe, and South Africa. 



Anyone anxious to start vines either in the open or 

 against walls will find in the book before us almost 

 every detail set out and every question answered. 

 The site for the vineyard and the nature of the soil are 



