208 CILIATE FIBRILLAR SYSTEMS 



Its pattern, although "constant and characteristic," is less regular and 

 "reminds one of badly treated chicken wire." 



Sectioned material showed the fibrils of both dorsal and ventral networks 

 "to be immediately under the pellicle and in contact with it." 



The fibrils stained intra vitam were distinctly more delicate than those 

 impregnated with the silver. 



Turner confirmed Yocom's observations on the neuronmotor apparatus, 

 excepting the motorium. In the E. patella which he studied, he was 

 unable to detect this cited organelle. Instead, the single fiber, formed 

 by fusion of the five anal cirri fibrils, was traceable to the "collar," 

 without a break, where it continued as the anterior memhranelle fbril 

 (Turner's designation) noted above. 



4. Vorticella. — The vorticellids, by their size and quick reactions, 

 caught the eye of the earliest microscopists, including, of course, 

 Leeuwenhoek. The sudden contraction of the spiraling stalk along with 

 the inversion and closure of the adoral membranelles naturally invited 

 speculations on the kinds of mechanisms that might account for such 

 reactions. Geza Entz (1893) cites Wrisberg (1765) as among the first 

 to describe "mit recht trefifenden Worden" this surprising behavior 

 and to point out its elastic nature. 



To Ehrenberg (1838), however, apparently should go the credit for 

 the earliest detailed studies of the fibrous nature of the contractile stalk 

 and the detection of longitudinal and circular fibers in the body of 

 several vorticellids. He attributed to all of these fibers a contractile 

 function and described in the stalk "muscle" cross striations comparable 

 to those of the striated muscles of other animals. 



This fibrillar complex in these peritrichs came to be a favorite object 

 of investigation by many able workers, especially during the latter half 

 of the past century: Dujardin (1841), Czermak (1853), Lachmann 

 (1856), Lieberkiihn (1857), Kuhne (1859), Rouget (1861), Cohn 

 (1862), Haeckel (1863), Metschnikoff (1863), Kollicker (1864), 

 Greeflf (1871), Everts (1873), Engelmann (1875), Wrzesniowski 

 (1877), Forrest (1879), Maupas (1883), Brauer (1885), Butschh 

 (1889), Schewiakoff (1889), and Entz (1893). The literature for this 

 period has been reviewed by Greefif (1871), Wrzesniowski (1877), and 

 Biitschli (1889). Similar investigations on the vorticellids have been 

 relatively meager during the present century, and the most detailed and 



