REVIEWS 719 



The contents of this well-produced volume include the whole of the original 

 matter composing the author's monograph on the house-fly (1907-9) ; but, owing 

 to the recent extensive additions to our knowledge of the subject, the preparation 

 of an entirely new work has been necessitated. The book is divided into six 

 parts, embracing twenty-seven chapters, and possesses an extremely useful biblio- 

 graphy covering thirty-seven pages and containing several hundred references. 

 The first part, after a brief historical sketch, introduces us to a minute and 

 well-arranged account of the anatomy of this insect and to a consideration 

 of its habits and bionomics. Among the sections which constitute the latter 

 subject, those relating to the range of flight and feeding habits receive more 

 particular attention. Part II. is devoted to the breeding habits and life-history 

 of the house-fly and to the structure of the mature larva. The first-named subject 

 is treated primarily from an historical point of view, and the more important 

 observations of various workers in this connection since the time of de Geer are 

 discussed. As a summary of these results, a list of the substances on which flies 

 breed is given, no less than forty-one being enumerated. The natural enemies 

 and parasites of this insect receive attention in the third portion of the book, and 

 a very interesting account of that important parasitic fungus Empusa muscce is 

 given. Among the many other species of flies which occasionally visit or frequent 

 houses, those of special economic interest are considered in Part IV., and accounts 

 are given of the Lesser House-Fly {Fannia canicularis, Linn.), the Latrine Fly 

 (Fannia scalaris, Fab.), the Stable Fly (Stomoxys calcitrans, Linn.), the Blow-Flies 

 {Calliphora spp.) and Sheep Maggot Fly (Lucilia c&sar, Linn.), the Cluster Fly 

 {Pollenia rudis, Fabr.), etc. The last two portions of the work (Parts V. and 

 VI.) deal respectively with the relation of house-flies to disease and control 

 measures. Considerable space is devoted to the former subject, in which, 

 besides their connection with various maladies, a discussion of the modes of 

 dissemination of pathogenic organisms by flies and particulars of some 

 miscellaneous experiments regarding the carriage of micro-organisms, pathogenic 

 and non-pathogenic, are given. 



The illustrations, most of which have been drawn by the author, are well 

 reproduced and decidedly enhance the value of the book. Four of the figures 

 (1, 48, 79, and 80) are coloured, and form three really beautiful plates, the first 

 forming the frontispiece and portraying the female house-fly. 



This volume is not intended as a popular treatise on the subject, since one 

 or two works of this nature are already in existence ; it is intended more especially 

 for the use of scientific workers, and to such it should prove of much value. 



H. F. C. 



BOTANY 



Transpiration and the Ascent of Sap in Plants. By Henry H. Dixon, 

 Sc.D., F.R.S. [Pp. viii + 216.] (London: Macmillan & Co., Ltd., 1914. 

 Price 55-. net.) 

 The problem presented by the rise of sap in plants has so many points of contact 

 with other branches of science besides that of plant physiology thai a wide circle 

 of readers will welcome this recent addition to Macmillan's Science Monographs, 

 in which Professor Dixon presents a discussion of this problem, to the solution of 

 which his own researches have contributed so largely. Even those who may be 

 unwilhng to concede that the theory elaborated by the author in conjunction with 

 Dr. Joly finally disposes of this much-debated problem, will at least admit that the 

 questions involved have been placed on a new footing, that the results of the 



