64 THE BIOLOGY OF STENTOR 



Very small species of Stentor, like multiformis, are not miniatures 

 of the larger since they contain fewer stripes which are therefore 

 relatively much wider in proportion to the cell volume. 



The lateral stripes tend toward a certain maximum number. 

 When stentors were cut in two longitudinally, slender fragments 

 were produced which had half the normal complement of stripes. 

 The aboral halves not bearing the mouthparts were followed 

 because stripe increase in them is more easily seen than in oral 

 halves with their finer stripes, as Stevens (1903) noted. Stripe 

 multiplication occurred at the line of heal (Tartar, 1956c), and in 

 5 days the specimens regained the normal width and number of 



Fig. 12. Increase in lateral striping. 



A. Non-oral longitudinal half has less than half the normal 

 number of stripes {a), h: New fine granular-stripes appear as 

 regeneration primordium forms at suture. Continued splitting 

 of granular bands with interpolated clear stripes {c) increases 



stripes to the normal number {d). 



B. Parabiotic graft of two oral halves has somewhat more 

 than the normal number of lateral stripes yet increases the com- 

 plement to near zN, in correlation with the double individuality. 



Stripes (Fig. i2a). When two of the oral longitudinal halves were 

 grafted together in homopolar parabiosis producing artificially a 

 more than normal sum of stripes, stripe increase still occurred 

 and very wide doublets with about twice the normal number of 



