FUSION MASSES OF WHOLE STENTORS 217 



opened to the outside through the ectoplasm near the posterior end. 

 These tubes were blue-green in color and obviously lined with 

 ectoplasm. In grafted pairs one or two tubes sometimes appeared 

 adventitiously (b). Sometimes the tubes had a neat opening through 

 the ectoplasm at both ends (c). Usually they opened near the 

 posterior pole and extended forward, suggesting gullet formation 

 in the normal site of oral differentiation. Their appearance may 

 represent acts of gullet formation entirely dissociated from anlagen 

 development. 



Internal ciliated vacuoles are equally surprising. These were 

 often found in large fusion masses and may have been due to the 

 accumulation of water inside. The vacuoles seemed at first to have 

 structureless walls, but they soon became lined with typical striped, 

 ciliated ectoplasm, as could easily be demonstrated by slicing 



B. Graft of two enucleated stentors which developed a single 

 tube, opening posteriorly, extending forward through the 

 endoplasm, and lined with ectoplasmic striping. The tube 

 contracted and extended with the mass, twisted through a 90° 

 arc autonomously, and seemed to "breathe" by independently 

 enlarging and narrowing. Elaboration of the structure in absence 



of a nucleus is paradoxical. 



C. Tube with neat opening through the ectoplasm at each 



end, developed in a 3-mass. 



D. Appearance of vesicle in a fusion mass. Initially the 

 vacuole seems to consist of a simple membrane enclosing fluid. 

 Later it becomes lined with ectoplasmic structure demonstrated 

 by ciliary circulation of mass of shed pigment granules within 



and by transection to expose ectoplasmic striping. 



E. Mass with two vesicles, one of which has broken through 

 the surface, the collapsed lining becoming continuous with 



outside ectoplasm and forming deep, ear-like cavity. 



F. Reorganization in Cyathodiniiim . Cortical ciliary 

 apparatus is resorbed and a new one formed inside as a vesicle, 

 lined with cilia and endosprits, which evaginates through the 

 lateral surface and produces a new cell axis at right angles to the 

 old. In division 2 endocellular ciliary anlagen are formed which 



move to opposite side. (After Lucas, 1932). 



G. Odd formation of tubes and vesicles lined with pigmented 

 ectoplasm and resembling an "archenteron" with one opening. 

 Differentiation of the oral anlage was incomplete. (After 



Tartar, 1954). 



