124 



BIOLOGY OF THE PROTOZOA 



membranelles and cirri, the number varying with the species. 

 Thus Maier describes 2 in the membranelles of Nyctoiherus cordi- 

 formis and many of them arranged in a row in the membranelle of 

 Sientor niger; in undulating membranes of the vorticellids Maier 

 and Schroder describe 3 rows of basal granules while in the "par- 

 oral" and "endoral" membranes of Glaucoma scintillans there are 

 5 and 10 rows of basal granules respectively (Maier). In the cirri 

 of Stylonychia histrio which are circular in cross-section, according 

 to Maier, there is a discoidal plate of basal bodies. Alverdes (1922) 

 found that an isolated cilinm will beat if the basal body is attached, 

 not otherwise. 



.;,••:; Uu l»ii 



*&/$/$ 



a 



a 



Fig. 69. — Cilia and myonemes of Infusoria, a, Membrane and periplast of Sim- 

 tor coeruleus; b, c, and e, rows of cilia of same; d, myoneme of same: /, optical section 

 of membrane and myonemes of same, and g, optical section of cortex of Holoplirya 

 discolor; m, myoneme; t, myoneme canal, (a, b, e, after Johnson; c, d, f, and g, after 

 Butschli.) 



A perplexing series of structures consisting of granules and con- 

 necting fibrils is found in some holotrichous ciliates. In Chla mydodon 

 mnemosyne, for example, a double row of granules with connectives 

 running around the body near the margin and visible in life as a 

 hyaline band, and a similar but more ladder-like structure is present 

 in the oral vestibule of Glaucoma frontata (Fig. 8, p. 29). It is 

 possible, but not demonstrated, that these structures belong to the 

 same category as the girdle around the posterior end of Yorticella 

 and represent the infraciliature (Chatton) or special tracts of the 

 silver line system. 



Mi/on fines.— One of the most striking characteristics of certain 

 types of ciliates is their power of contraction. A fully-expanded 



