588 BIOLOGY. 



Fam. 1. Monad-like Worms, Saugwiirmcr. 



Body tolerably smooth, suctorial mouth and sucker, 

 the intestine losing itself in the tissue of the body, and 

 without an anus ; androgynous. 



They remind us through their small size and structure 

 of the Monades, especially the Cercarise, and among the 

 Worms typify or prefigurate in particular the Hirudines 

 or Leeches, both by their form and power of suction, as 

 also in the ramification of the intestine. 



Many Cercarise might be metamorphosed into Disto- 

 mata, and so be or constitute their young. 



The Planariae are slightly different from the Liver- 

 flukes or Easciolse hepaticae, since they are white, blood- 

 less, have a ramified intestine without anus, and increase 

 also by fissiparous generation. They belong to the pre- 

 sent order, although they live not as parasites, but in a 

 state of freedom. 



Fam. 2. Rhizopodoid Worms, Hydatids. 



Body annulate or articulate, with a claviform pro- 

 boscis without an intestine ; they appear to have several 

 mouths. 



The Cystica develop ova simply upon the internal wall 

 of the tegument ; the body's last ring is expanded into 

 a cystic form, and is mostly much larger than the whole 

 body. The Ccenurus cerebralis, or Brain-hydatid, ramifies 

 like the Polyps. 



The Cestoidea have in each joint or member of the 

 body an ovarium, and, as it would appear, male parts 

 also, so that they are androgynous. The sexual orifices 

 are at the border or upon the surface of the posterior 

 members. The member can be viewed as an ovarium 

 liberating itself; as in the Lernese and Arguli. 



The Eilarise or Thread- woxms, which also belong here, 

 are in the form of a cylindrical tube, with separate sexual 

 parts, which open posteriorly. 



Fam. 3. Rotifer al Worms, Ascarides. 



Body cylindrical, intestine free, with mouth and anus ; 

 sexual parts separate. 



Upon the mouth these Entozoa have some papilla: or 



