X PREFACE 



The list of references appended to the end of each chapter has 

 been enlarged and is meant to aid those who wish to obtain fuller 

 information than that which is given in this volume. Since com- 

 prehensive monographs on various groups of Protozoa are widelj^ 

 scattered and ordinarily not easily accessible, the author has en- 

 deavored to provide for each group as complete an information as 

 possible for general reference purpose within the limited space, 

 and hopes that the present work has reference value for teachers 

 of biology, field workers in pure and applied biological sciences, 

 veterinarians, physicians, public health workers, laboratory tech- 

 nicians, and others. 



The author is under obligation to numerous writers for their 

 valuable contributions which have been incorporated in the text. 

 Special thanks are due Professor L. R. Cleveland, Harvard Uni- 

 versity; Professor R. P. Hall, New York University; Professor H. 

 Kirby, Jr., University of California; Professor L. E. Noland, Uni- 

 versity of Wisconsin; Professor H. J. Van Cleave, University of 

 Illinois; Professor D. H. Wenrich, University of Pennsylvania; and 

 Professor L. L. Woodruff, Yale University, for their valued criti- 

 cisms and suggestions. The author further wishes to express his 

 appreciation to Mr. Charles C Thomas, for his patient and kind 

 cooperation which has aided greatly in the completion and appear- 

 ance of the present work. 



R.R.K. 

 Urbana, Illinois, U.S.A. 

 July, 1939 



