218 CILIATE FIBRILLAR SYSTEMS 



Spasf7ionem or extends by means of the elastic pellicle. Accordingly the 

 longitudinal fibrils of the stalk sheath and the Spironem tend to reinforce 

 the elasticity of the Spasmonem, and the spiral myoneme of both sheath 

 and Spironem, upon relaxation of the longitudinal pair of myonemes, 

 tend to reinforce the elasticity of the pellicle. 



Entz's rather elaborate thesis at least makes evident the elaborate 

 differentiation of the vorticellid's stalk, and so provides one working 

 hypothesis which might be experimentally tested. With modern tech- 

 niques, this should not prove very difficult. And, in the writer's opinion, 

 the vorticellids offer extraordinary possibilities for some clear-cut and 

 fruitful experiments which should help toward a better understanding 

 of their fibrillar mechanisms. 



It seems to be more generally agreed that the fibrillar complexes of the 

 funnel, bell, and disc are primarily contractile. If so, and if the 

 Spasmonem of the stalk is, as Entz and others claim, continued without 

 interruption into the funnel and bell as the longitudinal fibrils of the 

 "inner complex," then it should follow that if these fibrils of the inner 

 complex are contractile, one should expect the Spasmonem also to be 

 contractile. Entz (1893) apparently does not discuss this point. 



Finally, it may be noted that Entz's thesis attributes no specific function 

 to the Axonem. Both he (1893) and Stein (1854) suggest that it might 

 function as a neuroneme. 



Observations on the fibrillar system of Stentor have provided a basis 

 for some interpretations which appear more plausible than those cited 

 above for the vorticellids. These interpretations have to do exclusively 

 with the myonemes. The other fibrils are poorly understood. 



Before discussing these, however, the essential components of this 

 system should be recalled to mind. As was pointed out, and as will 

 doubtless be familiar to the reader, the myonemes of Stentor are band- 

 like fibers which course beneath and slightly lateral to the longitudinal 

 rows of body cilia and the curved ciliary rows on the oral disc. 



Associated with these band-like myonemes, but lying peripheral to 

 and mostly contiguous to them, are other fibrils which Neresheimer 

 (1903) described as "neurophanes" and which Dierks (1926) recently 

 further described and named "neuroids," since he could not fully identify 

 these with Neresheimer's neuronemes. 



Dierks added one very significant observation, which, if verifiable. 



