36 ZOOLOGY. 
é 
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. 
r Prolongations of the body- 
s mass form the cilia, which 
ev characterize the Infusoria 
m and give the name to the 
e present order, Cuiliata. 
n Paramecium has an elon- 
gated, oval body ‘‘ with 
one end (/Z) 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 
a vesicle on the opposite 
ee rae side, next the convex 
Fig. 25.—Stentor polymorphus, magnified 130 back, whilst the general 
cutis emda oe De ents eee cavity of the body lice bo- 
and the dorsal edge in the distance. d, poste- 
rior end; sf, the tube enclosing d; ¢, the cili- tween these two.’ The 
ated border of the disk (s); v, the larger rigid : 
cilia; cv, the contractile vesicle in the extreme 2TTOWS 10 the figure repre- 
distance,seen through the whole thickness of the . 
body; co}, cv?, the posterior prolongation of cv, sent the course of the par- 
in the distance; ~, 71, the circular and radiating {] i i j : 
branches of what, by Clark, was supposed to be ticles of indigo with which 
froluctve-sjaam, extenting toi che ant, T< fod his specimens, 
sa a a Posten but toward the eye at 7}. as they are whirled 
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 
3 
ev? 
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