PREFACE 



DISEASES, both of men and animals, are sub- 

 jects that have come more to the fore in recent 

 years than in the past. The present book is the 

 outcome of our attempts made during the last few 

 years to satisfy the numerous inquiries made to us 

 for a scientific but readable account of the minute 

 animal parasites that produce diseases, detrimental 

 alike to man and beast. As the book has been 

 framed with the idea of being of service to many 

 different classes of readers, it is written in a semi- 

 popular yet scientific vein. Care has been taken to 

 explain fully the few technical terms that have been 

 used, and to repeat these explanations. 



The selection of subject-matter, naturally, has 

 presented some difficulty, but so far as possible that 

 side of the science of Protozoology, that comes in 

 direct contact with human life and needs, has been 

 chosen in preference to that which deals with the 

 more theoretical and speculative side. Diseases of 

 man, cattle, horses, poultry, game, fish, and bees, 

 due to parasitic Protozoa, thus occupy a large pro- 

 portion of the book. 



New illustrations have been used throughout this 



297303 



