PREFACE 



Many books and monographs devoted to protozoology 

 have appeared within the past few years; most of these 

 are excellent and valuable additions to the subject. 

 Various phases of protozoology are emphasized in the 

 books; some of them stress morphology, classification, 

 and life-cycles; others are devoted more particularly to 

 the biology of the free-living species; and several treat 

 especially the parasitic forms with emphasis on those that 

 live in man. Besides these contributions to protozoology- 

 alone, should be mentioned books and treatises on Trop- 

 ical Medicine, a large section of each being usually con- 

 cerned with the disease-producing protozoa of man. The 

 monographs are for the most part collections that bring 

 together the data regarding one important species or 

 group of organisms, whereas the books generally cover 

 the entire phylum Protozoa. 



Because of the numerous recent contributions to this 

 subject the writer feels under obligation to provide a 

 very good reason for adding another volume to the 

 already large library of protozoological books. He be- 

 lieves he not only has a valid reason for the preparation 

 of this volume but was practically forced by circum- 

 stances to undertake the task. The organization of 

 work in protozoology in a school of hygiene and public 

 health revealed at once a lack of coordination between 

 the zoological and medical phases of the subject and be- 



