PREFACE 



The subject of animal parasitology has in the past received 

 but scant attention in the courses in zoology in this country. 

 The student has had presented the general outline of the life 

 history of the pork tapeworm of man, of the liver fluke of the 

 sheep, and of trichina. As a rule he has seen only demonstration 

 specimens, covering but a portion of the life cycles of these 

 forms. 



The present generation has seen a revolutionary change of 

 attitude towards the subject. The remarkable discoveries of the 

 relation of insects and their allies to animal parasites of man, 

 the recognition that hookworm disease was widely preva- 

 lent in this country, and the extensive findings of other parasites 

 of man and of animals which resulted largely from the hookworm 

 campaigns, aroused a new interest in the parasites of man and 

 of animals. 



With this stimulus there has been an insistent demand for 

 more attention to parasitic forms by departments of zoology. 



In many of our colleges and universities special courses in 

 this subject are being offered and are being sought not only by 

 premedical and veterinary students, but by those interested in 

 public health work and animal husbandry. Increasing numbers 

 of students of general zoology are finding in such courses an 

 introduction to some of the most fascinating problems in their 

 chosen field of work. 



The demand for this special work has brought its problems 

 to the teacher. In many cases he has been at a loss as to where and 

 how to obtain material for his rapidly growing classes. Unlike 

 the standard materials of the first-year course, it was not to be 

 found in the regular biological supply houses. There was a general 

 feeling that it was rare and inaccessible to the average depart- 

 ment, and there was little idea as to what suitable forms were 

 available from domesticated or wild animals. There has been 

 almost complete dearth of suitable texts and at the present 

 time there is little choice in the way of a laboratory guide for a 

 general course in animal parasitology. 



