CILIATE FIBRILLAR SYSTEMS 207 



By these several methods Turner was able to disclose an "external 

 fibrillar network," which included: 



1. The "dorsal network," comprising (1) seven to nine longitudinal rows 

 of granular rosettes, from each of which protruded a central bristle; (2) seven 

 to nine longitudinal fibrils, uniting the bristles of the rosettes and designated 

 primary fibrils; (3) longitudinal secondary fibrils, running midway between 

 the primary fibrils; (4) commissural fibrils connecting, midway between the 

 rosettes, the primary fibril and on either side its secondary fibril, "pulling the 

 latter slightly out of line." The square meshes of this dorsal network, which 

 appeared remarkably constant, averaged about four microns across. 



2. The "collar," anterior to this dorsal network, comprising, (1) the 

 inclined row of parallel basal plates of the adoral membranelles, the lower 

 ends of which "rest" on the oral lip; (2) a posterior membranelle fibril, 

 connecting the "upper" ends of the membranelle basal plates; (3) an anterior 



post. m. fib. j(WFf'''^''^^^T^^^^(^^UWM^ 



mem, pi. -^^^gStJCTpiCSyCL' 



ant. m. fib. -^^^4^ H^Wrr / 



mec/. m. fib. ^^^^y^v-Jlrr^MiM^A^^^^ - - 3^1^- br. 



_-. ros. 



_ _ . com. ffb. 



JAJ^M^f^y^- sec. fib. 



-i-i—i—^--^'''^\ pri. fib. 



Figure 74. Euplotes patella: dorso-lateral view of external fibrillar system. (Turner, 

 1933.) 



ant. m. fib. — anterior membranelle fibril com. fib. — commissural fibril 



med. m. f. — median membranelle fibril mem. pi. — membranelle plate 



post. m. fib.- — posterior membranelle fibril pri. fib. — primary fib. 



ros. — rosette sec. fib. — secondary fibril sen. br. — sensory bristle 



membranelle fibril, connecting short commissures at the "lower" ends of 

 these basal plates; (4) a median membranelle fibril, attached on the basal 

 plates between the anterior and posterior membranelle fibrils. 



These anterior, median, and posterior membranelle fibrils continue this 

 same relationship with the membranelle basal plates throughout the course of 

 the membranelles along the ventral "lapel" down to their ending in the 

 cytopharynx (Fig. 74). 



Of primary importance is Turner's observation that his anterior mem- 

 branelle fibril is identical with Yocom's anterior cytostomal fiber, because this 

 obviously integrates structurally the neuromotor apparatus described by 

 Yocom and the external fibrillar system described by Turner. 



3. The "ventral network," which is entirely comparable, in its general 

 features, with the dorsal network, and includes also primary and secondary 

 longitudinal fibrils and rosettes, with their central bristles. 



