^"^- ^] Bovard. — Condylostoma patens. 347 



The relation which the myoncmes bear to the cilia is quite 

 different from that found in some other ciliates. In Stentor the 

 myonemes lie just below the basal bodies of the cilia, as show^n 

 by Johnson ( '93) and Neresheimer ( :03). It is clear, on surface 

 view, that the cilia in Condylostoma are to one side and not 

 directly above the myonemes ; the displacement is not very great 

 but sufficient to remove all doubt as to the exact location of these 

 elements. The myonemes form the primary ridges which mark 

 the surface and the cilia follow the furrows at the side of these 

 (PI. 34, figs. 1 and 2). In transverse sections the basal bodies of 

 the cilia are always below and to one side of the myoneme. 



The myonemes have the typical structure found in Hetero- 

 tricha. They are long threads which are oval in transverse sec- 

 tions and lie in small canals. It is almost impossible to make out 

 these canals in sections, but when a part of the ectoplasm is seen 

 in surface view, on either side of the deeply staining myoneme is 

 a very clear area. This area would correspond to the "Zwischen- 

 streifen" as seen in Stentor. Biitschli ('89) shows the relation 

 of myoneme and canal where the canal is of large size. This is 

 true for Holophrya discolor as well as Stentor cocruleus. In 

 these animals the myonemes are decidedly oval according to 

 Biitschli ('89) and Neresheimer ( :03) ; but Johnson ('93), (PI. 

 23, fig. 5), hoAvever, speaks of them as round and so figures them. 

 Neresheimer places the long axis of the oval perpendicular to the 

 surface, while Biitschli places it parallel to the surface. The 

 myonemes in Condylostoma are only slightly oval in section, the 

 long axis being perpendicular to the surface. No cross striations 

 have been observed in the myonemes of Condylostoma, although 

 they have been reported in other ciliates by Lang ( :01) and 

 Neresheimer (:03). 



Cilia. — Cilia are found all over the body with the exception 

 of the surface of the buccal funnel. They are arranged in rows 

 which follow the course of the myonemes and arise from furrows 

 which lie along the sides of the myonemes. These lines of cilia 

 run longitudinally when the animal is resting on the bottom of 

 the aquarium, l)ut when it is swimming run spirally around it 

 from right over to left. This change in the direction of the lines 

 of cilia is correlated with the change in the form of the body 



