X PREFACE 



To those physicians who diligently and honestly 

 endeavor to do their full duty by their patients but 

 who are widely and frankly confused as to what to do 

 and when to do it when they are confronted with the 

 finding of one or more of these organisms in an unwell 

 person, I hope this book may be of some assistance. 



To those who have become blinded by false report 

 or faulty or inadequate observation, I hope it will 

 bring serious reconsideration on the basis of the 

 scientific method. 



To those laboratorians connected with the medi- 

 cal profession as technical assistants I hope it may be 

 of use in studying the several protozoa of this system 

 which they are commonly called upon to identify. 



The author desires to express his thanks to the 

 Curator of the U. S. Army Medical Museum and to 

 Major G. R. Callender for the use of certain photo- 

 graphs, which are noted in their titles as having 

 come from the Museum, and to Dr. W. M. James, of 

 Panama, and others whose material has been freely 

 used. Appreciation is also expressed to Mr. J. M. 

 Hicks, a student at this College, for his assistance in 

 making the drawings for some of the illustrations, 

 which drawings were not usually made from indi- 

 vidual specimens of the various organisms but are 

 mainly conceptions as set down for him by the author 

 from study of actual specimens, usually a great num- 

 ber, assisted by the conceptions of other workers in 

 this field of protozoology. 



KENNETH M. LYNCH. 



Charleston, S. C. 



