94 



THE BIOLOGY OF STENTOR 



2. Analysis of the reorganization process 



There have been few experiments on reorganizing stentors and 

 this area of study is prickly with paradoxes, but I have some 

 unpublished data which is suggestive. These relate to the central 

 question whether resorption of mouthparts is uniquely character- 

 istic of animals in process of reorgnization. 



When the aboral half of the membranellar band is removed, an 

 oral primordium is formed and as it moves into place the original 

 mouthparts remaining are resorbed (Fig. 22A). Is this regeneration 

 or reorganization? Such cases are like regeneration in compensating 



A 



a ^ b ^ .' c ^ d 



Fig. 22. Observations relating to reorganization. 



A. When one half or more of the membranellar band is excised 



delayed formation of a regeneration primordium follows and 



original mouthparts are resorbed as in reorganization. 



Regenerant then gains a peristome of normal length. 



