vi PREFACE 



Under these circumstances the writers have felt that there 

 is a place for the "Guide to the Study of Animal Parasites" 

 which is here offered. It is the outgrowth of fifteen years of 

 experience on the part of the senior author in presenting the 

 subject to a group of students with varied interests, such as 

 is to be found in most of our schools. It is hoped that the sug- 

 gestions as to sources of material will considerably lighten the 

 work of the non-specialist who is called upon to present the 

 subject. They are also intended to aid the independent student 

 of zoology in getting an introduction to the field of parasitology. 

 It will be noted that the introductory study of the incidence 

 and distribution of the animal parasites of the frog is followed 

 by the study of the trematodes and that consideration of the 

 protozoan parasites is reserved for the later periods of the course. 

 We have found this the most feasible sequence for classes with 

 a background of only general zoology, but some instructors 

 may prefer to reverse this treatment. 



The omission of the arthropods from such a text needs expla- 

 nation. In most of the schools of this country where the subject 

 of animal parasitology is taught, the work in medical and veteri- 

 nary entomology is presented in a separate course. In any event, 

 there are available excellent outlines for the study of the ele- 

 ments of entomology. The protozoologic and helminthologic 

 aspects of the relation of arthropods to disease are those which 

 cannot be presented satisfactorily without more of a background 

 than most of the courses in medical entomology provide. 



It is with much reluctance that the authors have restricted 

 the references to literature to so small a number and these almost 

 exclusively in English. The original plan of citing original 

 monographs regardless of place of publication was discarded 

 because it was evident that most of these would be inaccessible 

 outside of research centers. The papers cited contain, in most 

 cases, special bibliographies, and many of the comprehensive 

 texts listed in the Appendix include very extensive references 

 to the literature. The student should be urged to consult 

 original sources and should have emphasized the importance of 

 preparation in modern languages if he expects to do advanced 

 work in any field of zoology. 



A section on the essentials of technique of collecting and 

 preparing animal parasites is appended. In addition there 

 is given a list of the more important parasites of laboratory 



