314 



THE BIOLOGY OF STENTOR 



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a ■ b ^ c d 



Fig. 89. Interactions in coeruleus X polymorphns chimeras. 



A. a : Three polymorphiis macronuclear nodes implanted into 

 an enucleated coeruleus with mouthparts excised, b: Wide 

 primordium forming in coeruleus cytoplasm under influence of 

 polymorphus nucleus, 12 hours later, c: Anlage not developing, 

 exudate in primordium site, and original coeruleus membranelles 

 fimbriated, d: Specimen died after 3 days and showed 6 nodes, 



indicating nuclear increase in alien cytoplasm. 



B. Mutual integration of shape, a: Polymorphus grafted at 

 right angles to coeruleus. b : Harmonization of shapes and spread 

 of chlorellae throughout, c: Oral structures dediflferentiated, 

 coeruleus pigment lost, chlorellae clumped, d: Prompt death of 



species combination. (After Tartar, 1953, 1956c.) 



coeruleus cytoplasm. If pigmentation is a sign of taxonomic related- 

 ness, the blue-green color of both introversus and coeruleus suggests 

 that these species are more closely related than others, and this 

 could be the basis for effective interaction between their parts. 

 The species multiformis is also blue-green and in fact appears like 

 a miniature of coeruleus, with but a single macronuclear node. 

 These animals are so small that a whole cell had to be implanted 

 in the enucleated coeruleus. In 4 cases no regeneration occurred, 

 but we have to remember that regeneration on one node is greatly 

 retarded so that in this combination the chimeras may have run 

 into difficulties of another sort before they were able to express 



