Vlll PREFACE 



Protozoenkunde have been most extensively employed. Numer- 

 ous illustrations have been copied from the last mentioned work 

 and the text itself has been closely followed in many places. 



The attempt has been made to give proper credit for borrowed 

 illustrations, but the numerous cuts retained from the previous 

 editions of Williams have not been specially designated. Some 

 references have been included, to offer the student a ready intro- 

 duction to the literature of the topic under discussion, especially 

 in those instances in which the topic has been only briefly men- 

 tioned here. 



My thanks are due to the Press of Gustav Fischer, Jena, for 

 the loan of numerous illustrations, to P. Blakiston's Son and 

 Company for their uniform courtesy in our relations, and espe- 

 cially to my wife whose enthusiastic assistance has made possible 

 the preparation of the manuscript and has lightened the burden 

 of seeing it through the press. 



W. J. MACNEAL. 

 NEW YORK 

 December, 1913. 



