THE CANADIAN ENTOMOLOGIST. 295 



we should expect the best possible account of this insect and its disease- 

 carrying proclivities, and to say that he has not disappointed us is only 

 half of the confession. The remaining half is known by those who know 

 the author, and will soon be discovered by the readers of this book who 

 have not that good fortune. "This book," the introduction states, '"is not 

 intended to be a scientific monograph ; it is simply an attempt to tell in an 

 understandable way what is known about the subjects indicated in the 

 title." Such a book, giving in a readable and complete fashion an account 

 of the house-fly, its habits and development, its relation to disease and 

 methods of control, was greatly needed, and we are glad that such an 

 account is now available for the general reader. The first hundred pages 

 are devoted to the fly, its life-history and habits and its natural enemies. 

 The succeeding chapter gives a most complete and succinct account of the 

 carriage of disease by flies, which, by its extent, will surprise many readers 

 who have not devoted much attention to the subject. In an excellent and 

 most practical chapter the various means of preventing and eradicating 

 this potential disease-carrier are described and fully discussed ; this 

 chapter is probably the most valuable contribution to this question which 

 has yet been made, and we sincerely hope that it will find its way into the 

 hands of sanitary authorities and others, upon whom the solution of this 

 problem largely depends. An account of other species of flies inhabiting 

 houses is given and is fully illustrated. The illustrations are excellent and 

 well chosen. We have, however, one serious criticism to make : by force 

 of habit we turned to refer to the index ; there is no index. 



C. Gordon Hewitt. 



The Tse-tse Flies. 



"A Handbook of the Tsetse Flies (Genus Glossina),'" by Ernest E. 

 Austen. X+ i lo pp., lo coloured plates and 24 figs, in text. British 

 Museum (Natural History) London, 191 i. 



In no branch of medical entomology and pathology has so rapid 

 progress been made during the past few years as in the causes of those 

 dread diseases, the human disease known as Sleeping Sickness, and the 

 disease of domestic animals, known by the native name "Nagana." These 

 diseases are caused by microscopic protozoal organisms called Trypano- 

 somes, which are carried by several species of Tse-tse flies. The Tse-tse flies 

 are i elated to our own Sto?/ioxys, but are confined to the Ethiopian region. 

 Among the Diptera they are most remarkable for their method of repro- 

 duction j instead of depositing eggs the female produces a single full-grown 



