36 



ZOOLOQT. 



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 a 

 central mass 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 {R) 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 



Fig. 2S. —Sten'oy polynuyrph-ua, magniliol 130 back, whilst the general 

 diameters, expanded and bent slightly over to- „„„:i„ „f 4-|,„ \,nc\v liVa Vip 

 ward the observer; the mouth m, uext the eye, OdVibJi oi tiie uuuj^ lies ue- 



and the dorsal edge iu the distance, d, poste- -f^./jo-n +Vio(ja ¥-arr\ " TVio 

 rior end; sA, the tube enclosing d ; c, the cili- ''"^^en inese tWO. -Lne 



ated border of the disk (s); v, the larger rigid Q-pvnw! in tlip fio-iirp rpurp 

 cilia; ct, the contractile vesicle in the extreme ^^i""" ^"- ''"^ iisUie lepie- 

 distance.seen through the whole thickness of the gg^t the COUrse of the par- 

 body; cw^.cTj'*, the posterior prolongation of cu, ^ .... 



in the distance; r, 7-', the circular and radiating ticlcs of indiffO with wllich 

 branches of what, by Clark, was supposed to be r^-. ■, » -. -. . 

 a rudimentary nervous system; n, ii', the re- Clark fed hlS Specimens, 

 productive system, cxt«ndiiig fi^om the right ,, ^ i • i j 



side, at n, posteriorly, but toward the eye at K'. aS they are WhirleQ 

 —After Clark. , t_j.ii •t. 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 



