February 5, 1920] 



NATURE 



591 



various chemical or mechanical factors. The 

 importance of the presidence of the nervous system 

 is well seen in the reduced efficiency of the body 

 during fatigue, and in the enhanced efficiency in 

 circumstances where interest or emotion is 

 aroused ; in chap. xi. there is included a brief 

 discussion of the subject of industrial fatigue, on 

 which so much useful work has been done during 

 and since the war, and one of the conclusions, that 

 " the establishment of a uniform length of working 

 day for all classes of manual workers would lead 

 in many cases to inefficiency " (p. 183), is worthy 

 of careful note. 



The subject of training is discussed in chap, ix., 

 and in chap. xii. it is shown that the differences 

 between the circulation in the trained and un- 

 trained man can be extended to explain the con- 

 dition of effort syndrotne, or soldier's heart, in 

 which the heart becomes inadequate to its work 

 abnormally soon, owing to an impaired state of 

 its nutrition. 1 



Considered as a whole, the work is extremely 

 good ; it is well written, the viewpoint is broad, 

 and the management of the arguments clear and 

 convincing ; indeed, a possible fault is that the in- 

 expert reader may be misled as regards the com- 

 plexity of the problems dealt with in such a clear 

 and simple manner, or fail to appreciate what 

 a vast deal of work lies behind some of the seem- 

 ingly plain and obvious conclusions. Should this 

 prove to be the case, it is but an indication of 

 the excellent way in which the author has treated 

 his subject. The references are to modern work 

 chiefly, and in every respect the book is thoroughly 

 up-to-date. Prof. Bainbridge is to be congratu- 

 lated most heartily on having added to these valu- 

 able monographs such a cleverly written exposi- 

 tion of a difficult subject. 



THEORIES OF SOUND PERCEPTION. 



Some Questions of Phonetic Theory. Chap. v. 

 The Perception of Sound. By Wilfrid Perrett. 

 Pp. 39. (Cambridge : W. Heffer and Sons, 

 Ltd., 1919.) Price 25. net. 



THIS work may be regarded as a continuation 

 of the interminable discussion regarding the 

 functions of the cochlea, or more particularly the 

 part of the internal ear concerned in hearing. 

 Theories of sound perception may be divided into 

 two classes : first, those which assume that some- 

 how analysis takes place in the cochlea ; and 

 secondly, those that relegate the analysis to the 

 brain. The first theory also assumes that the 

 principle of sympathetic resonance is the founda- 

 tion of the method by which the organ of Corti 

 in the cochlea works, while the second theory, as 

 • NO. 2623, VOL. 104] 



it involves ganglion-cells and part of the brain, 

 has no experimental basis on which to rest, and 

 leaves the function practically insoluble. The 

 resonance theory owes its clear inception to 

 Thomas Young and its development to Helm- 

 holtz. While it explains many experimental facts, 

 and has been supported by many physicists and 

 physiologists, it has now and again been assailed 

 by critics who have advanced some form of the 

 second theory, and founded their objection to 

 the older theory mainly on facts which appar- 

 ently cannot be accounted for by the Young- 

 Helmholtz theory. 



Mr. Perrett supports the second theory, 

 and denies the existence of any resonating 

 mechanism in the cochlea. In a short notice it 

 is impossible to meet all his points, but it seems 

 he does not meet the difficulties of the case. No 

 explanation is offered of the extremely complicated 

 organ of Corti, unless it serves some such purpose 

 as is implied in the older theory ; there are obvi- 

 ous difficulties relating to the fibres of the 

 cochlear nerve ; and the explanation is hopeless 

 when we reach the ganglionic mechanism of the 

 brain. On the other hand, the resonance theory, 

 on the whole, meets the facts, and, if not free 

 from objections, as Helmholtz and his supporters 

 admit, it serves the purpose of a good theory by 

 stimulating research, while it satisfies the mind. 

 The same may be said of the retina and the 

 action of light, and, indeed, of all the end-organs 

 of special sense. Mr. Perrett, while he has evi- 

 dently studied the subject, historically and other- 

 wise, seems unduly biased against a fair present- 

 ment of the older theory, and we recommend 

 caution and a wider view. J. G. M. 



KASHMIR AND INDIAN SILKS. 



The Silk Industry and Trade : A Study in the Eco- 

 nomic Organisation of the Export Trade of 

 Kashmir and Indian Silks, with Special Refer- 

 ence to their Utilisation in the British and 

 French Markets. By Ratan C. Rawlley. Pp. 

 xvi-|-i72. (London: P. S. King and Son, Ltd., 

 1919.) Price I05. 6d. net. 



THIS volume forms a natural complement to the 

 official report on Indian silk by Prof. Max- 

 well Lefroy and Mr. E. C. Ansorge recently pub- 

 lished by the Government of India. In the official 

 report the Indian silk trade is dealt with 

 primarily from the Indian trade point of view; 

 ill the volume now under notice Indian silk 

 is considered in its relation to the markets of 

 Great Britain and France. As is well known, raw 

 silk from India at the present day does not occupy 

 a high place in the estimation of manufacturers, 

 and it was with the object of ascertaining the 



