Foreword 



The author had the privilege of delivering the Dunham 

 lectures at Harvard University during the academic year 

 1947-1948. One of the lectures, given under the title ''Visi- 

 ble self-reproducing cytoplasmic granules in the life cycle 

 of some parasitic ciliates," is the nucleus around which the 

 book has been built. 



It was not possible, in the course of one lecture, to 

 discuss, or even to mention, all the aspects of the problems 

 raised by the ciliates. The author has therefore been 

 pleased to take the opportunity kindly offered by Doctors 

 Goddard, Schmitt, and Weiss, as advisory editors of the 

 Wiley Biological Research Series, of organizing some of 

 these problems into this monograph. He was especially 

 pleased because many of the data related to ciliates are in 

 perfect agreement with the theoretical conceptions of Dr. 

 Paul Weiss, chairman of the Advisory Board, concerning 

 what he has called "molecular ecology." 



This monograph is not a treatise. No attempt is made 

 to cover all the aspects of the subject or to give an exhaus- 

 tive survey of the literature. The author's work on the 

 morphology and biology of the ciliates started in 1921 and 

 extended over many years. Having for some time followed 

 other roads, he has, nevertheless, the impression that a 

 somewhat aged and matured knowledge of the ciliates is 

 not without advantages. Ciliates are very nice animals in- 

 deed, but, like other delicate creatures, they have to be 

 treated with a buffered and balanced mixture of love and 

 experience. 



The author expresses the hope that his American friends, 

 to whom this book is dedicated, will find some austere 



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