36 



ZOOLOO Y. 



cavated a mouth and a throat leading to a so-called stomach 

 or digestive cavity. Two hollows in the body form the con- 

 tractile vesicles, and an- 

 other cavity constitutes 

 the reproductive organ. 

 Prolongations of the body- 

 mass form the cilia, which 

 characterize the Infusoria 

 and give the name to the 

 present order, Ciliata. 

 Paramecium has an elon- 

 gated, oval body "with 

 one end (H ) flattened out 

 broader than the other, 

 and twisted about one 

 third way round, so that 

 the flattened part resem- 

 bles a very long figure 8." 

 In this form, as well as in 

 Stentor (Fig. 25), as Clark 

 remarks, " we have the 

 mouth at the bottom of a 

 broad notch or incurva- 

 tion, and the contractile 

 vesicle on the opposite 

 side, next the convex 

 magnified 130 back, whilst the general 

 body lies be- 

 two." 



sh 



Fig. 25. 



diameters, expanded and bent slightly over to- p -^ n f 

 ward the observer; the mouth m, next the eye, CaVlt} OI 

 and the dorsal edge in the distance. , poste- x +VPP 



rior end; sh, the tube encl - ^Ween inefee 



ated border of the disk (s) 



TViP 



. , 

 rior end; sh, the tube enclosing a ; c, the cili- 



); v, the larger rigid q rv nw3 in flip ficrnrp rpnrp 

 cilia; c, the contractile vesicle in the extreme ariows 



distance,seen through the whole thickness of the opnf thp rnnrsp of thp rtftr- 



body; c ? ,ca, the posterior prolongation of c, SenL inG 



in the distance; r,r, the circular and radiating tides of indigo with which 



branches of what, by Clark, was supposed to be 



a rudimentary nervous system; n, n l . the re- Clark fed lllS Specimens, 



productive system, extending from the right i i i 



side, at n, posteriorly, but toward the eye at n l . as tllCV are Whirled 



After Clark. J .. ., 



along, by the large vibrat- 



ing cilia (v) of the edge of the disk, against the vestibule of 

 the mouth." During the circuit the food is digested, a 

 mass of rejectamenta is formed near the protuberance, a, 

 which has appeared a short time before. This finally 



