MORPHOLOGY 



61 



fibers" in the ectoplasm of Stentor which were later named 

 myonemes (Haeckel) or neurophanes (Neresheimer). 



The myonemes of Stentor have been studied by several in- 

 vestigators. According to Schroder (1906), there is a canal between 

 each two longitudinal striae and in it occurs a long banded myoneme 

 which measures in cross-section 3-7/x high by about lju wide and 

 which appears cross-striated (Fig. 14). Roskin (1923) considers that 



mc 



gis 



Fig. 14. Myonemes in Stentor coeruleus (Schroder), a, cross-section of 

 the ectoplasm; b, surface view of three myonemes; c, two isolated 

 myonemes (cl, cilium; gis, granules between striae; k, kinetosome; m, 

 myoneme; mc, myoneme canal). 



the myoneme is a homogeneous cytoplasm (kinoplasm) and the wall 

 of the canal is highly elastic and counteracts the contraction of the 

 myonemes. All observers agree that the myoneme is a highly con- 

 tractile organella. 



Many stalked peritrichous ciliates have well-developed myonemes 

 not only in the body proper, but also in the stalk. Koltzoff's (1911) 

 studies show that the stalk is a pseudochitinous tube, enclosing an 

 inner tube filled with granulated thecoplasm, which surrounds a cen- 

 tral rod, composed of kinoplasm, on the surface of which are ar- 



