CHAPTER I 



INTRODUCTION 



What are stentors good for ? 



One would like to say that these exquisite little organisms are 

 a sufficient wonder in themselves and that to study them as a part 

 of nature is an expression of natural curiosity and that happy 

 relationship between subject and object which carries its own self- 

 justification. Doubtless this delight sustains the investigator 

 throughout what would otherwise be the weary and protracted 

 pursuit of other ends. Moreover, the experience of science has 

 shown that pursuing a subject for its own sake is likely to turn up 

 clues to which a more ulterior approach would be blind. 



Yet this hobby-like vitality of interest is not sufficient. Our 

 studies become truly exciting and fruitful to others only when 

 they lead to general principles on the theoretical level. Of necessity 

 we have to start with some specific organism, woefully unique in 

 itself, out of the immense variety of existing forms of life, yet we 

 want our study eventually to be relevant to general problems of 

 biology. 



To rew^ord the question, we may ask what particular advantages 

 Stentor may have with respect to these larger ends, that an entire 

 book should be devoted to this one type of organism. 



Most outstanding is that on stentors one can easily perform a 

 wider range of micrurgical operations than on any other uni- 

 cellular organism or tissue cell, remarkable though the experiments 

 with Amoeba and the single-celled alga Acetabularia have been. 

 These operations are made possible by what for lack of a more 

 subtle analysis we have to call the consistency of the endoplasm 

 which permits grafting whole animals or cell parts in any number, 

 combination, or arrangement desired. The relatively large size 

 of these cells is a help, though the largest are no bigger than the 

 period at the end of this sentence. Stentors, unlike amcEbas, 

 exhibit a high degree of visible cytoplasmic differentiation and in 



