6o THE BIOLOGY OF STENTOR 



may represent a unique contractile structure the elucidation of 

 which might define a specific parameter of muscle physiology. 

 This is the orientation of Randall and his co-workers. Or by 

 emphasizing diflFerences in the parts of descendant individuals one 

 might explore new aspects of genetics such as the importance of 

 cytoplasmic inheritance, as in the work of Sonneborn ; and poten- 

 tially this approach could be most fruitful in Stentor in which 

 micrurgical exchange of cytoplasms and nuclei is not difficult. 



One may also consider all the fine structure from the standpoint 

 of epigenetics or morphogenesis. Obviously the criterion of re- 

 generation and other types of epigenetic performance, is the fine 

 structure also what "does" the morphogenesis? Is the fine struc- 

 ture the cause or the result of morphogenesis? For instance, in the 

 simple healing of an incision in Stentor the ribbon bundles and 

 their many fibers in the clear stripes apparently rejoin; therefore in 

 addition to their function of conduction and contraction have these 

 fibers also the capacity for guiding their reintegration? In some 

 way of which we have yet no understanding all the fine structure is 

 integrated, an obvious inference from the integrity of the organism 

 and its normative tendencies which will receive specific documenta- 

 tion as we proceed into the experimental studies. It is as if, in 

 addition to its specific physiological functions, every meridional 

 unit of a stentor " knows " when one of the mouthparts is missing 

 or the oral structures are misplaced, for all seem to cooperate in 

 correcting the deviation from the norm, some parts, often quite 

 distant from each other yet somehow in effective communication, 

 taking the leading roles. 



For example, if the head is rotated i8o° on the body, the 

 mouthparts disconnect from the membranellar band, migrate into 

 the frontal field and are resorbed — ^this specific disjunction and 

 taking down of structures being in its way a compounding of the 

 marvel of their original construction. Then, in a far distant part 

 of the cell a new oral primordium begins on some signal, and 

 experiment indicates that all parts of the cortex support anlage 

 formation and are involved in the timing of its development. 



But this is to anticipate a part of our story, yet such phenomena 

 pose the further problem of the integration of all the parts of 

 Stentor in terms of the fine structure w^e have described if not 

 some further principle. 



