METABOLISM 277 



(c) Amorphous stentors 



These bizarre specimens first appeared in crowded samples in 

 small dishes which were kept for two weeks or more without added 

 nutrient (Tartar, i959f). They have also sometimes developed in 

 animals isolated on slides. The usual course of changes leading to 

 gross abnormalities is shown in Fig. 77A. The animals are first 

 noticed as longer and narrower than usual. Then appears a central 

 mass of compact pigment granules which later becomes sharply 

 delimited from the surrounding cytoplasm. The form is increas- 

 ingly long and snake-like. Eventually much of the cytoplasm is 

 concentrated at the anterior end in a bouton, while a long tail 

 dangles behind resulting in a characteristic tadpole or vorticellid 



A. Course of development, a: Possible initial stage in which 

 internal pigment granules accumulate among the carbohydrate 

 reserves, h: Narrow " snake " form with sharply bounded pig- 

 ment mass but normal-appearing macronucleus. c: Bulbous 

 * 'tadpole" form with long tail and transverse stripe arrangement 

 anteriorly, d: Increasing abnormality of shape and defective 

 stomatogenesis though nuclear nodes appear normal, e: 

 Recovery of one such specimen, with pigmented core lost, 

 normal feeding organelles and nearly normal shape. /; Usual 

 course tow^ard completely amorphous condition showing 



projecting processes and followed by death. 



B. Transmission of abnormality to normal stentor. a: 

 Amorphous stentor grafted in place of head of a normal, in ratio 

 of about 1:8 by volume, h: Gross abnormality developed 

 throughout by next day. c: "Tadpole" stage, with new reorgani- 

 zation peristome but no mouthparts. d: Amorphous by day 4 

 of the experiment, pigmented core now rather diffuse. Specimen 



later recovered somewhat but died on the slide. 



C. Similar abnormality produced by grafting normal 

 polymorphiis to normal coerideus. a: Enucleated polymorphus 

 without symbionts grafted to coerideus in proportions by volume 

 of 1:4. b: Reorganized as a doublet with good integration of 

 shape, but almost all of the cerulean pigment lost by influence 

 of the graft, c: Elongated form with large core of unpigmented 

 granules. Nuclear nodes appear normal, d: Development of 



amorphous condition. Time-span shown: 7 days. 



D. Photograph of amorphous coeruleus in various stages of 

 development: a: elongated cell; b: bulbous form; c: complete 



loss of normal form. 



