October 4, 1S94J 



NA TURE 



545 



book ; but to Cornish ears it will sound as oddly as if he 

 alluded to a 2-feet rule, or to a 2-years old colt, or as 

 if he spoke of a Guardsman as a "six-feeter." 



A very full and accurate index greatly adds to the 

 value of the work. The insertion of the names of von 

 Cotta, von Croddeck, and von Sandberger under the 

 letter V is, however, open to objection. 



Prof. Le Neve Foster is to be congratulated on having 

 enriched our technical literature with a contribution of 

 substantial value. Undoubtedly the best book on the 

 subject in the English language, it bears comparison with 

 the treatises of Gallon and Haton de la Goupillicre in 

 French, and with those of Serlo and Koehler in German. 

 It should find a place in every mine office, and, by being 

 carefully studied by mine managers, should help to raise 

 the British ore and stone mining industries from their 

 present depressed condition. 



Bennett H. Brough. 



DR. ABLER' S OBSERVATIONS ON 

 GALL FLIES. 

 Alternating Generations : a Biological Stiidv of Oak 

 Galls and Gall Flies. By Hermann Adler, M.D., 

 .Schleswig. Translated and edited by Charles R. 

 Straton, F.R.C.S., £d., F.E.S. With illustrations. 

 (Oxford: Clarendon Press, 1894.) 



THE order Hymenoptera has never been a popular 

 study, in the sense in which the Colcoptera and 

 Lepidoptera have become so during the last century, 

 but it probably numbers among its votaries nearly three 

 times as many students as any of the remaining 

 orders. Nor is this surprising, for although it cannot 

 compete with the Lepidoptera in beauty of colouring, it 

 surpasses the Coleoptera in its variety of form, and is 

 probably more numerous in species than any other 

 order. It supplies us with some of the most valuable 

 products which are yielded by insects, such as honey 

 and ink, and stands at the head of the insect world, both 

 in intelligence and in diversity of habits. 



The Aculeata, or ants, bees, and wasps, and, after 

 these, the TenthredinidiT, or saw-flies, have generally re- 

 ceived most attention from those entomologists who have 

 specially devoted themselves to the study of the Hymen- 

 optera:. But within the last twenty or thirty years, several 

 entomologists have occupied themselves with the studv 

 of the Cynipidce, or Gall Flies, and have discovered a 

 system of alternate generations in these insects almost 

 as remarkable as that which had previously been 

 observed in the Aphididie, or Plant-lice, which belong 

 to the very different sub-order Iloinoptera. 



One of the most important contributions to this sub- 

 ject was Dr. Adier's treatise, " Ober den Generations- 

 wechsel des Eichen-GalKvespen," which was published 

 in the Zeitschrift fitr wissenschaftliche Zoologie for 

 1881 (vol. XXXV ), with three coloured plates ; and it is 

 this work which Dr. Straton has now brought within the 

 reach of every English entomologist. 



As a rule, works on many branches of science become 

 obsolete shortly after publication, and are seldom re- 

 quired except by specialists ; but this does not apply to 

 observations on transformations and habits. Men who 

 have sufficient patience, taste and opportunity to make 

 NO. I 30 I. VOL. 50] 



such observations of real value are few and far between, 

 and their results, if sufficiently accurate, remain of per- 

 manent value, however much they may be enlarged by 

 future observations. Hence Dr. .Straton has rendered a 

 real service to science by publishing an English edition 

 of a work of this description, which was originally issued 

 several years ago in a costly periodical, which would 

 hardly be accessible, even to those who can read the 

 original, except [in metropolitan or university libraries. 

 Dr. Adier's work has been carefully and accurately trans- 

 lated, including his descriptions of the insects observed, 

 his table of alternating generations, and his observations 

 on gall-formation, oviposition, &c. ; and the coloured 

 plates have been faithfully reproduced, though the 

 original stones had been destroyed. 



Dr. Straton has added an introduction, a chapter on 

 Cynips Kollari, synoptical tables of galls, a classification 

 of the Cynipidce, and a bibliography and index. The 

 introduction deals with the history of the study of galls, 

 and the questions of parthenogenesis, alternating genera- 

 tions, &c., in arthropods, and more especially in the 

 Cynipidce, the changes in the ovum and sperm-cells being 

 described in detail, with reference to the views of Weis- 

 mann and others ; and Dr. Straton's own remarks will be 

 found interesting to embryologists in general. Incidental 

 remarks on gall parasites, and other points unconnected 

 with the main subject of the book, are occasionally 

 introduced. 



We have only to regret that it has not occurred to Dr. 

 Straton to add the principal bibliographical references to 

 descriptions, &c., of each species, and a note as to 

 whether it is common or rare in England. These ad- 

 ditions, which might have been placed between brackets, 

 to distinguish them from Dr. Adier's work, would have 

 added to the usefulness of the book, which may probably 

 penetrate to country places where the information which 

 it contains cannot be supplemented by reference to larger 

 works ; to which, however, it is very necessary to refer 

 the student, that he may know what to consult if he 

 wishes to pursue the subject further. This want is only 

 imperfectly supplied by a bibliography, absolutely neces- 

 sr.ry as this is for advanced students, and also to indicate 

 the extent of an author's reading, and the sources froni 

 whence he has derived his information. 



W. F. K. 



OUR BOOK SHELF. 



Hygiene. By J. Lane Notter, M.A., .M.D., .and R. H 

 Firth, F.R.C.S. Pp. 37+. (London : Longmans, 

 Green, and Co., 1S94.) 



Primer 0/ Hygiene. By Ernest S. Reynolds, M.D. 

 Pp. 158. (London: Macmillan and Co., 1894.) 



Though it is not expressly stated that Dr. Xotter's book 

 "has been designed to meet the requirements of the syllabus 

 of the Science and Art Department," the work is issued 

 in the series of manuals published by Messrs. Longmans 

 for students working up for South Kensington examina- 

 tions, from which fact it may be inferred that such 

 students will use it as a text-book. And as the author is 

 an examiner in hygiene under the Department of Science 

 and Art, his book doubtless contains the kind of know- 

 ledge that commands marks. Therefore teachers would 

 do well to adopt it for their classes ; and all writers of 

 other text-booki covering the same ground may regard 



