PREFACE* 



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This bulletin has been prepared for the use of physicians 

 and public health workers who are called upon to -diagnose 

 diseases caused by Protozoa and worms. No attempt has 

 been made to include in the keys and descriptions all of the 

 species that are now known. On the contrary, species that 

 have been recorded only once or a very few times have been 

 purposely omitted to avoid confusion. 



The information and figures contained in this bulletin 

 have been selected from original articles in periodicals, and 

 from reference and text books wherever available. Credit 

 for the use of figures is given in every case in the descriptions 

 of the figures. A few of the more important books and 

 articles relating to the parasites described are listed at the 

 end of the account of each group. Other lists will be found 

 in the bibliographies contained in most of these books and 

 articles. So far as possible we have verified statements 

 regarding the organisms described, but errors are almost 

 certain to creep into such a compilation, and we will welcome 

 corrections. We will also be glad to accept any suggestions 

 for the improvement of the bulletin which may be incor- 

 porated in a second edition if called for. 



The methods employed by various workers for the diag- 

 nosis of parasitic Protozoa and worms are very numerous 

 and only a few could be described in this bulletin. These 

 have been selected on the basis of simplicity and effective- 

 ness. It seems to us desirable that methods applicable to 

 field conditions and requiring x the minimum of apparatus 

 and reagents should be emphasized. Modifications of these 

 methods may be devised to fit the circumstances encountered 

 in the field. 



* The publication of this bulletin was made possible by a grant 

 from the International Health Board. 



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