372 THE CANADIAN ENTOMOLOGIST. 



BOOK NOTICE. 

 House Flies and How They Spread Disease. By C. G. Hewitt, 

 D. Sc. (The Cambridge Manuals of Science and Literature, 

 Cambridge; the University Press. One shilling.) 



Although in the last few years the public has at last become 

 more or less awake to the fact that the house fly is not merely a 

 troublesome nuisance but a serious enemy of mankind, few even 

 among the educated realize the many ways in which this ubiquitous 

 insect can make itself a source of danger to public health. The 

 present little book is just what has been needed to bring this 

 important matter home to the public mind and we believe it will 

 have a far-reaching influence in increasing such efforts as are being 

 made to keep this pernicious insect under control. 



The book is not a record of new observations, the subject 

 matter having already been set forth at much greater length in Dr. 

 Hewitt's earlier work — "The House-fly: A Study of its Structure, 

 Development, Bionomics and Economy."* It is written for the 

 benefit of the layman, and it has been the author's endeavour "to 

 avoid as far as possible the use of technical terms unfamiliar to 

 the lay mind and the inclusion of matter which is of interest chiefly 

 to the specialist." In this aim we think he has been eminently 

 successful, the book being written in a clear, simple style, as easy 

 to read as a novel. 



Of the two parts into which the book has been divided, the 

 first deals with the natural history of the fly; the second with its 

 relationship to disease. In Part I. the author has wisely restricted 

 the description of the fly's structure and metamorphosis to such 

 features as are necessary to a proper understanding of the general 

 facts of its life history. In this part are also given short accounts 

 of other species of flies commonly found in houses and of the para- 

 sites and natural enemies of the house-fly. In Part II. the relation- 

 ship of flies to a number of diseases is discussed, a special chapter 

 being devoted to the important role which they play in the dis- 

 semination of typhoid fever and the summer diarrhoea of infants. 

 In the last chapter is a full description of the methods of control 

 which a thorough study of the fly's life history have proved to be 

 most efficient in destroying it. 



The little volume, which is small enough to be carried in one's 

 pocket, has a most attractive appearance, the paper and print 

 being of excellent quality and the illustrations, with few exceptions, 

 are reproduced from the beautiful plates which accompanied the 

 authors earlier work on the house-fly (I.e.). The quaint design 

 on the title page is a reproduction of one used by the earliest known 



CambridR:e printer, John Siberch, 1521. 



*Manchester Lniversity Press, Biological iSeries, No. 1, 1910. 

 Mailed December 31st, 1912. 



