ANALYSIS OF STENTOR 



233 



Stroke may vary but this would be difficult to detect. The distance 

 between membranelles in the same phase is the metachronal waz'e 

 length. Speed with which metachronal rhythm passes along the 

 band is the wave velocity and is equal to the product of frequency 



hme - /requAncy ot bead: 

 distance - ssripLiiiuLe 



A 



propulsive, stroke r^coveri/ 

 l^AV£ LENGTH 



stroke 



■^ Wave vetoed If = ^-eqaen^i/ of beat X wavelength- 



Fig. 67. Actions of the peristomal membranelles. 

 Analysis of successive beating or metachronal rhythm. 



B. Swimming backward with ciliary beat reversed and 



membranelles stopped and pointed forward. 



C. Forward swimming with membranelles active and pointing 



backward. 



D. Coordination in transected sections of the peristome, a: 

 Metachronal rhythm maintained, moving distally from pace- 

 maker in the oral region, b: Isolated section sets up independent 

 rhythm, pace set by proximal membranelles. c: Beating of 

 membranelles still independent, as in the whole peristome when 

 beating recommences. Rhythm will be re-coordinated by new 



pacemaker at x. 



