332 



NATURE 



[November 27, 1919 



also may suggest that the hills once studied by 

 Prof. Watts should be called "the Breidden," not 

 "the Breiddens." But these remarks are not 

 criticisms. The book will prove a charming and 

 trustworthy companion to any observant traveller 

 in the beautiful native county of Charles Darwm. 



S. 

 H. 



Oim BOOKSHELF. 

 Tri-lifigual Artillery Dictionary. By E. 

 Hodgson. With introduction by Col. J. 

 Mansell. In three volumes. Vol. i., English- 

 French-ltalian. Pp. viii + 92. (London: Charles 

 Griffin and Co., Ltd., 1918.) Price 55. net. 

 With the progress of every department of 

 engineering, new technical terms are being con- 

 tinually introduced into the languages of various 

 nations. In the case of artillery, the difficulty 

 of intercommunication which thus arises is con- 

 siderably increased owing to the conditions under 

 which international relations become necessary in 

 the progress of military operations. Any reader 

 who thinks himself to be a good French or Italian 

 scholar will receive a rude awakening if he opens 

 any page of this book. Even among the most 

 commonplace technical terms he will find the 

 French and Italian equivalents to be quite different 

 from anything that would naturally have been 

 imagined. It is quite evident that much of the 

 work of preparing such a book falls within the 

 definition of original research. 



It might be possible for officers of various 

 nations to make each other understand their 

 meaning by pointing to a gun or a model 

 or a drawing, but the use of the telephone 

 renders this method inadequate. By making 

 this dictionary of the size of a quarter- 

 plate photograph, Mr. Hodgson has given 

 officers a book which they can easily carry about 

 and use in communicating with their French and 

 Italian colleagues. The latter ought, of course, 

 to have corresponding books also. It is, moreover, 

 quite certain that a companion volume for German 

 will be urgently needed under any conditions 

 which the future may have in store. 



Apropos of dictionaries, the following sugges- 

 tion is not without a certain significant aspect, 

 namely, that a dictionary is wanted between the 

 language of the Tripos type of mathematical 

 examination paper and the language of the 

 engineering factory. The difference of language 

 certainly does harm. G. H. Bryan. 



The Mycetozoa: A Short History of their Study 

 in Britain; an Account of their Habitats Gene- 

 rally; and a List of Species Recorded from 

 Essex. By Gulielma Lister. (Essex Field 

 Club Special Memoirs, vol. vi.) Pp. 54. 

 (Stratford, Essex : The Essex Field Club ; 

 London: Simpkin, Marshall, and Co., Ltd., 

 1918.) Price 35. net. 



The Essex Field Club has done well to reprint 

 as a whole the subject-matter of Miss Lister's two 



NO. 2613, VOL. 104] 



presidential addresses, and in this way to render 

 them available to a larger public than the readers 

 of the Essex Naturalist. 



The list of species recorded from Essex is 

 mainly of county interest, but it is the county 

 to which Miss Lister and a number of friends who 

 .have been inspired by her work and that of her 

 father have devoted special attention, and there- 

 fore serves as an object-lesson to naturalists in 

 other counties. The tabulated lists at the end. 

 of the book of the species recorded from similar 

 areas in the Home Counties, the West of England, 

 and the North of Scotland respectively, indicate 

 what may be done by a few enthusiasts in the 

 study of this interesting little group at the base 

 of organised life. 



But the greater part of the volume is of wider 

 interest. The first section, on the study of Myce- 

 tozoa in Britain, is an historical resnnid of their 

 study in this country, from the time of John Ray, 

 who refers to one of our commoner' species in his. 

 "Synopsis of British Plants" in 1696, and of 

 Dillenius, who figures several species in an en- 

 larged edition of the "Synopsis " in 1724, to the- 

 classic " Descriptive Catalogue of the Mycetozoa, 

 by Mr. Arthur Lister, in 1894. This monograph, 

 in the preparation of which Miss Lister shared, 

 and the handy little "Guide to the British 

 Species" have done much to extend the study 

 of the group, both in Great Britain and abroad^ 

 as is indicated by the rapidly increasing number 

 of species in successive editions of the "Guide," 

 the fourth of which is now being issued by the 

 Trustees of the British Museum. 



The second section, on the habitats of the 

 Mycetozoa, will be of great service to workers in 

 indicating where to look for these organisms, and 

 what species are likely to be found in spyecial 

 environments. The habitat varies remarkably, 

 including woodlands, alpine pastures, moorland, 

 rocks, bare earth, sawdust- and straw-heaps, 

 manure, and even bone. A useful list gives 

 a selection of the habitats with the associated 

 species. 



Guide to the Study of the Ionic Valve: Showing 

 its Development and Application to Wireles.^ 

 Telegraphy and Telephony. By W^. D. Chven. 

 Pp. vii-1-59. (London: Sir Isaac Pitman and 

 Sons, Ltd., n.d.) Price 2s. 6d. net. 

 This little book is divided into fifteen chapters, 

 each chapter consisting §ii three or four para- 

 graphs of large print describing the historical 

 development of the ionic valve, the principles on 

 which it works, and the various types of valve 

 that are now used in wireless telegraphy. The 

 diagrams are clear, of large size, and not over- 

 crowded with details. References are given to 

 the original papers describing the various forms 

 of valves and their developments. The book can 

 be recommended to all who intend to take up the 

 serious study of radio-telegraphy, as it will im- 

 press the main facts about the ionic valve on their 

 minds. 



