INFUSORIA. 



shell, have one or several whips, or lashes, and a row of 

 cilia, with which they lash themselves along with great 

 velocity. 



Order II. Suctoria. This order is represented by 

 the Acineta (Fig. 7), beautiful, trumpet-like animals re- 

 sembling the purest glass. 



From the body project F G 



numerous slender tufts 

 that are not cilia, but hol- 

 low tentacles (arms), hav- 

 ing in some a sucker at 

 their ends. Their prey 

 is grasped by the arms, 



that contract, each at the FIG. i.Acir.ta. F, attached by stalk ; 

 same time sinking into ^ encysted, 



the body of the victim, 



pumping or sucking out its juices. They multiply by self- 

 division, while some species have free-swimming young. 



Order III. Ciliata. These are the true Infusorians, 

 easily observed with a common microscope, a drop of 

 standing water furnishing myriads. They are either 

 free and covered with cilia, or stalked, with the cilia 

 about the head. They have a mouth, a digestive cavity, 

 or stomach, and multiply by self-division or budding. 

 Among the free swimmers, the Paramedums (Fig. 8) are 

 the giants, and easily observed if a little carmine is intro- 

 duced into the drop. As they dart about, we see that 

 they are oblong, narrowing at the head, the back rising 

 into quite an elevation, beneath which, upon the under 

 side, is the mouth. From the head and on all sides are 

 minute prolongations of the body, or cilia, arranged in 

 rows, organs of locomotion. The Vorticellce (Fig. 9), or 

 bell animalcules, are bell-shaped, and held by a long, 

 slender, glass-like stalk, by which they contract. A colony 

 of them presents a curious sight ; the bells are continually 

 contracting, as if jerked from behind, the stalk forming a 



