ANALYSIS OF STENTOR 24I 



Hofer (1890) recommended hydrochlorate of hydroxylamine 

 (0-25%) neutralized with sodium carbonate for slowing the cilia 

 and relaxing myonemes in coeruleus. Of several related compounds 

 Mugard and Courtney (1955) found that only KH2PO4 was a 

 sufficiently non-toxic immobilizer of all ciliates tested, including 

 stentors. 



Methyl cellulose, first introduced for quieting paramecia by 

 Marsland (1943), remains the least noxious method for slowing 

 cilia in stentors. Its use will be discussed in the chapter on 

 techniques. 



4. Anaesthesia of myonemes 



Stentors, like Spirostomum and the stalked Vorticellids are 

 capable of very strong and instantaneous contraction. In my 

 experiments with stentors I have been impressed by the observa- 

 tion that contractility seems to be one of the last functions to 

 disappear, and even grossly abnormal and necrotic specimens, no 

 longer capable of swimming with their cilia or of regenerating, 

 nevertheless continue to react to poking with the needle by rapid 

 and vigorous contraction, almost up to the time of their final 

 demise. 



Attempts to anaesthetize the myonemes and abolish contraction 

 have been pursued both for the purpose of fixing and staining 

 animals in the fully extended state and to test whether stentors 

 behave like a typical nerve-muscle preparation. 



It will be recalled that Neresheimer (1903) found what he 

 thought to be nerve-like fibers which he called " neurophanes " 

 running to the myonemes, and later Dierks (1926a) described 

 similar fibers (" neuroids ") running exterior to the myonemes and 

 terminating in or sending branches to them. That these fibers with 

 their putative function represent specialized organelles and not 

 mere artifacts of fixation is still very questionable (see p. 55), yet 

 they led Neresheimer to an extensive study of the effects of drugs 

 on Stentor coeruleus which may have its merits apart from the 

 conclusion he drew. Control animals were first placed in a small 

 dish on a platform to which a graduated stick was fastened in a 

 vertical position so that a weight on a pulley could be dropped 

 from a measured height onto the platform, the vibration of which 

 would then stimulate the animals to contract. The minimum 



