228 



THE BIOLOGY OF STENTOR 



Fig. 66. Consequences of rotating anterior part i8o° on the 

 posterior. 



A. Equal halves rotated, mouthparts excised, a: Pigment 

 stripes of like width join and mend, wide and narrow stripes 

 match up, 2 to i, without joining, b: Regeneration is delayed 

 because membranellar band left intact, hence single primordium 

 arising only in relation to the extending posterior striping, 

 anterior stripes resorbing. c: Completion of regeneration with 

 anterior striping nearly replaced by growth of posterior striping. 



B. Stentor transected somewhat anterior to center; anterior 

 striping resorbed though no primordium is formed since feeding 

 organelles left complete. Head therefore does not make anterior 

 striping dominant yet effectively inhibits anlage formation in 



the posterior portion, isolated by rotation. 



