50 THE BIOLOGY OF STENTOR 



diagram the accounts of these two groups insofar as they concern 

 fibers lying under the clear stripes. 



It is now seen that the bands immediately underlying the clear 

 stripes are of lamellae, stacked edgewise and attached to each other 

 as well as to the pellicle by their outer margins, their inner edges 

 lying free. Each lamella is composed of a stack or layer of very 

 fine fibrils, regularly spaced, adjacent lamellae being connected by 

 even finer processes. 



According to the French workers the main body of this 

 lamellation, which we shall refer to empirically as the ribbon 

 bundle, constitutes the "ectomyoneme", a contractile organ of 

 unique structure. Number of lamellae varies with the level of the 

 body. The ribbon nearest the ciliary row, somewhat different in 

 shape and often separated from the other lamellae, was identified 

 as the kinetodesma which they supposed to connect the kine- 

 tosomes or basal bodies of the cilia, and the whole was referred to 

 as the myocihary complex. This connection was demonstrated 

 by the British workers whose photographs indicate that all 

 lamellae in the pile achieve connection with cilia. They therefore 

 called the ribbon bundle the '' km band ", suggesting that all parts 

 are possibly involved both in ciliary coordination and in contrac- 

 tion. Fibers leave the bundle and bifurcate as they attach to 

 opposite sides of a kinetosome, corresponding to the peduncles 

 observed by Villeneuve-Brachon (1940) in light microscopy. It 

 was further suggested that a given fiber may terminate forward on 

 one kinetosome and posteriorly on another, presumably facilitating 

 coordination of ciliary beating. 



Either the restricted kinetodesma of Faure-Fremiet et ah or 

 the entire km band of Randall and Jackson follows the rule of 

 desmodexy (Chatton and Lwoff, 1935b) in that the fibrous con- 

 nectives between the kinetosomes lie to their right ; but otherwise 

 the system is entirely different from the infraciliature of other 

 ciHates, with the exception of Spirostomum (Randall, 1956). In 

 other forms the interciliary fiber or kinetodesma appears simple 

 and single, and transverse connectives between the kinetodesmata 

 are often found. According to the pioneer work of Worley (1933, 

 1934) on coordination of body cilia in Stentor and two other 

 ciliates, stentors do have these connectives and a metachronal 

 wave down a line of cilia can escape around a small surface 



