THE CILIATE INFUSORIA. 



35 



II 



III 



n 

 m 



cv 



H 



ers, so that when the organism has by means of its hollow 



arms or tentacles caught some 



Infuaorian, the arms con- 



tract, draw the victim nearer 



to the Ac-ineta, and when the 



sucking disk at the end of the 



arms has penetrated the skin, 



the contents of the body of 



the Infusorian are sucked into 



the food-cavity of the Acine- 



ta ; on the other hand, in 



some Acinetse a portion of the 



arms are simply prehensile. 



These animals are in their 



adult phase quite unlike the 



Flagellata or Ciliata, but the 



young are developed within 



the parent and are provided 



with cilia, being at first free- 



swimming, and afterward 



fixed by a long stalk. The 



Acinetce sometimes self -di- 



vide, sending off from the 



free end of the body a ciliated 



Acinete ; they have also been 



seen to conjugate. 



Order 3. Ciliata (Infuso- 

 ria). A common type of this 

 group and one easy to obtain 

 by the student is Parame- 

 cium (Fig. 24), observed in 

 infusions, or moving rapidly 



ii i i n i r it;. ^*. ruTU'iiteviiuii, vuuuutu/ii. . 



OVer the bodies Of larger am- view from the dorsal side, magnified 340 



mals which may be under the SS&, 

 microscope. Figure 24 rep- 



rpcpnt Pnrnmeriiim rniirlrt vesicles; I, II, III, the radiating canals of 



raramecium cauaa- CTl . n ' tl ; e re p roductive orga %. , the 



tum Ehrenberg. This ani- lareevibrating^iliaattheedgeoftlieves. 



tibule. After H. J. Clark. 



malcule is a mass of proto- 



plasm, representing a single cell. In the body-mass are ex- 



Fig. 24. Paramtcium caudatum. A 



* fi&5t 



