September 22, 1923] 



NA TURE 



433 



case it is surely confusing to apply the term " anterior " 

 to the anal interradius. Such differences of opinion 

 cannot, however, detract from the value of a book 

 which is essentially a clear and accurate statement of 

 things seen. F. A. Bather. 



hes Zoocicidies des plantes d'Afrique, d'Asie, et d'Ocianie. 

 Par Prof. C. Houard. Tome i : Cryptogames, 

 Gymnospermes, Monocotyledones, Dicotyledones 

 (i"" partie), Nos. i a 1806. Pp. 496. Tome 2 : 

 Dicotyledones (2* partie), Index bibliographique, 

 Nos. 1807 a 3293. Pp. 497-1056. (Paris : J. 

 Hermann, 1922-1923.) 2 vols. 100 francs. 



During the years 1906-1913, Prof. Houard, professor 

 of botany in the University of Strasbourg, placed all 

 cecidologists deeply in his debt by the issue of his three 

 fine volumes on " Les Zoocecidies des plantes d'Europe 

 et du bassin de la Mediterranee." He has now covered 

 Africa, Asia, and Australasia. Only America remains, 

 and it is to be hoped that Prof. Houard will continue his 

 indefatigable labours and encompass the zoocecidology 

 of the globe. The present work is based essentially on 

 the same plan as its predecessor : a short introduction 

 and table of abbreviations, and then a descriptive 

 catalogue of the animal galls of plants, the latter 

 arranged systematically according to Engler and 

 Prantl's " Pflanzenfamilien." This is followed by a 

 bibliographical index of more than seven hundred 

 memoirs of which Prof. Houard himself may be justly 

 proud to claim sixty-five items ; by zoological and 

 alphabetical tables of the animal organisms producing 

 galls on plants, an index of plant hosts, and a general 

 index. The volumes are illustrated by a portrait 

 frontispiece and nearly two thousand figures, which 

 although small are quite adequate. 



Three thousand two hundred and ninety -three 

 galls are described, and by his ingenious system of 

 abbreviations, and rather rare power of indicating the 

 chief morphological features in a few words. Prof. 

 Houard manages to convey, often in a line or two of 

 print, quite an astonishing amount of information 

 concerning the structure of the gall, its geographical 

 distribution and the causal agent. To each description 

 is appended the bibliography of the particular gall with 

 a note of the memoirs in which a figure is to be found. 



Looking through the bibliography one is a little 

 dismayed to find how little British cecidologists have 

 contributed toward a knowledge of the galls found in 

 lands within the British Empire. There are, of course, 

 exceptions, as the well-known names of Lounsbury, 

 Froggatt, Fuller, Green, Maskell, and others indicate, 

 but one must confess that one would like to see British 

 names a little more prominent and numerous. The 

 volumes are very well produced, and botanist and 

 zoologist alike will thank Prof. Houard for placing in 

 their hands so valuable a contribution to so fascinating 

 a subject. 



La Radiologic et la guerre. By Mme. P. Curie. (Nou- 

 velle Collection scientifique.) Pp. 144 + xvi Plates. 

 (Paris : Felix Alcan, 192 1.) 8 francs net. 



The distinguished author of this little book narrates 

 briefly the part which the X-rays played in the medical 

 services of the French Army during the War, or more 



NO. 2812, VOL. I 12] 



correctly the radiological experiences which she her- 

 self had during those momentous years as technical 

 director of the radiological work of the Patronage 

 National des Blesses. 



The book commences with two short chapters on the 

 nature and production of X-rays. Then follows an 

 account of typical installations employed in hospitals 

 and lorries in the field. A chapter is given up to a 

 description of radiological work in hospitals and is 

 devoted mainly to methods of locaHsing foreign bodies 

 and the examination of fractures. Mme. Curie ex- 

 presses herself in favour of a preliminary fluorescent 

 screen examination before resorting to photography — 

 a subject on which there is a division of opinion in 

 Great Britain. There is a paragraph on the protective 

 measures essential for the X-ray operator. It is now 

 well known that complete protection may be secured ; 

 and in Great Britain at any rate, there has latterly been 

 a steady improvement in the working conditions in 

 hospitals and elsewhere, thanks to the work of the 

 X-ray and Radium Protection Committee and the 

 National Physical Laboratory. 



Later chapters in the book deal with questions of 

 personnel and organisation of X-ray departments. 

 Brief mention is made of radiotherapy and radium 

 therapy. As was the case with the British army, when 

 the value of the X-rays had been realised there was an 

 enormous expansion of the French radiological services 

 during the War ; and Mme. Curie quotes some striking 

 figures in this connexion. For example, she estimates 

 that in the course of the years 1917 and 1918, well over 

 one million X-ray examinations were conducted by the 

 organisation under her direction. 



The nation's appreciation of war achievements is 

 now dulled, but this little book prompts the suggestion 

 that an account of the British radiological activities 

 during the War should be put on record. 



G. W. C. K. 

 Light and Colour. By Dr. R. A. Houstoun. Pp. 



xi + 179 + io plates. (London: Longmans, Green 



and Co., 1923.) 75. 6d. net. 

 Dr. Houstoun's book deals with wide aspects of the 

 science of light and colour, and will be found of interest 

 by photographers and medical students as well as by 

 members of the public generally. There is an excellent 

 chapter on invisible rays, including a description of 

 Prof. Rankine's method of wireless telephony and Dr. 

 Foumier's optophone, by which a blind man is able to 

 read ordinary printed matter, such as books and news- 

 papers. A very clear and simple account of the X-ray 

 spectrometer is included, and also an account of the 

 current views of the structure of the atom. Primary 

 and complementary colours are described by the author, 

 who gives the usual table of complementary colours — 

 that of Ilelmholtz — while he states that Helmholtz is 

 not so definite on the subject as is generally supposed : 

 he does not give the defects of Helmholtz's methods, by 

 which indeed no consistent results can be obtained. 

 In ascertaining complementary colours it is absolutely 

 necessary that a comparison white light of known 

 composition be used. Without this there is only a 

 mental estimation of the white, in other words guess- 

 work. 



Colour blindness and various methods of detecting 



