296 THE BIOLOGY OF STENTOR 



dividing, was used to replace that of a divider it was divided with 

 the cell. 



These findings indicate that the cytoplasm as a whole, or its 

 state of activation-inhibition with reference to primordium forma- 

 tion, seems to be involved in guiding the nucleus in its behavior. 

 Thus, in some of my own unpublished studies reorganizers or 

 dividers were cut in two longitudinally before the nucleus had 



Fig. 84. Behavior of the macronucleus of ^S. coeruleus in absence 

 of the oral primordium. 



A. a: Stage-2 reorganizer cut in two longitudinally, b: 

 Non-oral half retains nucleus in nodulated state while that of 

 oral half clumps as reorganization proceeds to stage 5. c: But 

 the non-oral half soon shows a tardy coalescence of nodes and 

 then renodulates along with the partner half (d). e: Fragment 

 without mouthparts forms regeneration primordium 10 1 hours 



later with nodes again fusing. 



B. Macronucleus renodulates in longitudinal half of a divider 

 without the primordium, regenerating later. Stage-6 anlage 



completes development without nucleus. 



C. Nodes coalesce and renodulate in half without primordium, 



while mouthparts rejoin membranellar band. 



