REVIEWS 



The Practical Study of Malaria and other Blood Parasites. By J. W. W. 

 Stephens, M.D. Cantab., D.P.H., and S. R. Christophers, M.B.Vict., I. M.S. 

 Third Edition. [Pp. 414.] (London, 1908 : Published for the University 

 Press of Liverpool by Williams & Norgate ; price 12s. 6d.) 



THE third edition of The Practical Study of Malaria and other Blood Parasites, 

 by Christophers and Stephens, differs in some important respects from the previous 

 edition. The knowledge of parasitology, and of the intermediate hosts of parasites, 

 has steadily increased, and a book of this nature has necessarily, therefore, to 

 include fresh subjects with each edition. 



The authors, in this instance, have been able to make this increase without 

 adding materially to the bulk of the book, by excluding subjects previously dealt 

 with. Of these exclusions the most important is the chapter dealing with Filaria. 

 These parasites are important clinically, and the recognition and differential 

 diagnosis of the embryos found in the blood are, in many tropical diseases, of con- 

 siderable importance, whilst the methods of examination required, though simple, 

 are of value. It is a difficult matter to decide on such a question, but it is to be 

 hoped that the authors may find it practicable to restore the chapter in future 

 editions. The actual space saved, however, is considerable, as the necessity for 

 dealing with many groups of the Culicidae is diminished, and attention can be 

 confined to the most important group, the Anophelina. 



The arrangement of the book is much the same as in the previous editions. 

 Malaria is considered fully. Not only are the parasites described in detail, but 

 also the changes they induce in the corpuscles in which they live. A special 

 feature is an elaborate analysis of the leucocytes in malaria considered in a later 

 chapter (Chap. XXI I.). 



The mosquitoes are considered in detail as regards some of the anophelines 

 only and Stegomyia calopus. As these mosquitoes are the carriers of malaria and 

 yellow fever respectively, a knowledge of them is necessarily required in the study 

 of these diseases, and in the space of a book of this kind it is impossible to include 

 the enormous number of species, or even genera, that are now known. Theobald's 

 classification is followed. A very valuable part of the work is the description of 

 the larvae of the anophelines. As the different species vary greatly in the part they 

 play in the propagation of malaria, it is of great practical importance to be able to 

 diagnose the species from the larvae instead of by the tedious and often difficult 

 process of waiting till they have hatched out. 



The dissection and anatomy of the mosquito are fully described, as well as the 

 characters of the zygotes and sporozoites of the malaria parasites. 



A useful chapter is that on the method of making a " malarial survey " of 

 a station, illustrating well the importance of determining species and the proportion 

 of mosquitoes infected with malaria. The authors prefer for this purpose the 

 determination of the sporozoites rather than of zygotes and capsules of zygotes, 

 which, however, have the advantage that they can be recognised more certainly 

 by a beginner. 



The chapter on blackwater fever is an excellent one, and indicates lines for 

 future work. 



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