November 3, 1923] 



NA TURE 



649 



in this volume. He then turned to experimental 

 work on the ventral nerve-cord of the rock-lobster 

 Palinurus, a'nd on the reflex mechanism of the chela 

 of the crayfish. He built a private laboratory on the 

 shore of Lake Como, but his scientific work was inter- 

 rupted by another project — he founded the Rivista 

 di Scienze biologiche and wrote for it many critical 

 articles and reviews. The death of his father and of 

 his faithful laboratory assistant caused him to suspend 

 his researches, and he turned largely to philosophy. 

 His friends have decided to reprint a selection of his 

 earlier papers and of his unpublished work, and the 

 present volume, which is excellently produced, forms 

 the first instalment. It consists of eleven original 

 papers — on the subjects noted above and on graft 

 hybrids, their significance in regard to heredity and 

 acquired characters, the transformation of the wild 

 bee into the hive bee, etc. — sixteen reviews and articles, 

 and a reprint of his thesis on progressive heredity. 



Handbuch der Zoologie : eine Naturgeschichte der 

 Stdmnie des Tierreiches. Begriindet von Prof. Dr. 

 Willy Kiikenthal. Herausgegeben von Dr. Thilo 

 Krumbach. Erster Band : Protozoa, Porifera, 

 Coelenterata, Mesozoa. Erste Lieferung. Pp. 192. 

 (Berlin und Leipzig : Walter de Gruyter und Co., 

 1923.) 95. 



This forms the first ^art of Vol. L of a handbook of 

 zoology, to be completed in five volumes, in the pre- 

 paration of which about forty authors have agreed 

 to take part. An introduction (50 pp.) to the Protozoa 

 by Prof. Rhumbler is followed by an account (60 pp.) 

 of the Rhizopoda by the same author and of the 

 Flagellata bv Dr. V. Jollos, and by the first few pages 

 of the section on the Sporozoa by Prof. M. Hartmann. 

 After the general account of each order is given a scheme 

 of classification into sub-orders, groups, families, and, 

 in some cases, genera, with short diagnoses of each. 

 While the treatment of most of the groups is adequate, 

 the very brief account of Entamoeba is not consonant 

 with the importance of this genus, of which no figure 

 is given. The latest references in the list of works 

 on Rhizopoda relate to papers published in 19 16, and 

 this suggests that publication has been delayed. The 

 section on the flagellates contains a number of good 

 new figures, and the list of references includes papers 

 published in 1921 and 1922, but the account of the 

 collared flagellates is very short and inadetjuate. 



Plane Geometry for Schools. By T. A. lieckett and 

 F. E, Robinson. Part IL, with Answers. Pp. 

 viii-f 241-453 + v. (London: Rivingtons, 1922.) 55. 



Messrs. Beckett and Robinson's interesting attempt 

 to combine the main propositions of formal geometry 

 with the extensions included in the easier portions of 

 '■ modem plane geometry " and with the fundamental 

 notions and applications of trigonometry, is continued 

 in the second part of their work. The first part was 

 noticed in these columns on June 10, 1922 (vol. 109, 

 p. 737). The second part consists of three sections. 

 Section iv. deals with areas, extensions of Pythagoras's 

 theorem, and the properties of chords and tangents of 

 circles, with incidental reference to radical axis, 

 graphical solution of (|uadratic equations, etc. In 



NO. 2818, VOL. I 12] 



section v. we have inequalities, maxima and minima, 

 and regular polygons. Section vi. deals with ratio and 

 proportion : applications to trigonometry are then 

 given, as well as centres of similitude, inversion, pole 

 and polar (with a little on anharmonic ratio). The 

 treatment is pleasant and masterly, and the whole 

 work can be highly recommended. S. B. 



Printing Telegraph Systems and Mechanisms. By H. H . 

 Harrison. (Manuals of Telegraph and Telephone 

 Engineering.) Pp. xii + 435. (London: Longmans, 

 Green and Co., 1923.) 215. net. 



This volume will be most useful as a work of reference 

 to designers of telegraph machinery. It will also be 

 useful as a text-book in telegraph administrations. 

 The book has been very carefully compiled ; the 

 diagrams, of which there are 420, are excellent, and the 

 latest modem applications including high frequency 

 multiplex methods, both for land and submarine cables, 

 are fully described. There is now considerable over- 

 lapping of the sciences of telephony, telegraphy and 

 radio-communication, many of the same devices being 

 used in each. It must be admitted that at present, 

 development in all branches of the art of communica- 

 tion is taking place most rapidly in the United States. 

 Communication service in that country is such a large 

 undertaking that systematic research can be carried 

 on intensively on a scale that excites the wonder and 

 envy of European engineers. In Britain, the home 

 demand for apparatus is comparatively on a much 

 smaller scale. 



Experimental Physical Chemistry for Students in the 

 Medical and Allied Services. By Dr. B. S. Neuhausen. 

 Pp. 53. (Philadelphia: H. N. Rudley, 614 Arch 

 Street, 1923.) i dollar. 



Dr. Neuhausen 's work is in the form of a pamphlet 

 rather than of a book. The physio-chemical exercises 

 which he describes are all related directly to bio- 

 chemistry or medicine ; thus, measurements of freezing- 

 point depression, electrical conductivity, the con- 

 centration of hydrogen, sodium and chlorine ions, 

 viscosity, refractive index, etc., are all carried out with 

 serum rather than with more commonplace solutions ; 

 and the rate of inversion of cane-sugar is studied in 

 the form of an inversion by invertase in place of the 

 more familiar inversion by acids. In view of the 

 growing importance of physical measurements in bio- 

 cliemistry the appearance of a work of this character 

 may be heartily welcomed. 



A Text-book of Physics. By Dr. R. S. Willows. Third 

 edition. Pp. viii-f-48 + 488. (London: E. Arnold 

 and Co., 1923.) 95. net. 



The call for the third edition of this useful text-book 

 has given the author an opportunity to add a chapter 

 on the conduction of electricity through gases. The 

 McLeod gauge is first described and a brief account is 

 given of the electric discharge in a vacuum tube. Then 

 follow experiments on kathode rays and positive rays, 

 and paragraphs dealing with X-rays, ionisation in 

 gu.scs and radioactivity. A chapter of a similar kind 

 on electromagnetic waves may be suggested for a future 

 edition. 



