OF THE FLAT WORMS. 



One species, the echinococcus of man, E. hominis, inhabits 

 the viscera of man, and especially the liver. 



850. The cysticercus has the body rounded or depressed, 

 rugose, terminating in a caudal vesicle; its head (like that of 

 the armed tsenia) is furnished with four suckers and with a re- 

 curved proboscis. It inhabits solitarily a very thin cyst. 



Thecysticercusofthecellulartissue,C. ce//t//osa?, has the head 

 square, the neck very short and inflated before, the body cy- 

 lindrical elongated, the caudal vesicle elliptical transversely, 

 and is the species so common in the hog; it is met with some- 

 times in the muscles, the brain, and the heart of man. Some 

 other species are also found in the human body. 



851. The rough diceras, D. rudis, has the body ovoid 

 and depressed; it has a loose tunic; its head is provided with 

 a bifid, rough, filamentous horn. It is not exactly known 

 whether it inhabits the substance of organs. It was discover- 

 ed by Sultzer, in the matters discharged by the action of a 

 purgative. Considered doubtful by Rudolphi, it has been 

 found since by Le Sauvage, de Caen, who has sent individuals 

 to the Societ6 de la Faculte de Medecine, where I saw them. 



II. OF THE FLAT WORMS. 



852. The flat worms are those whose soft and depressed 

 bodies is provided with sucking-pores at its inferior surface 

 or at its extremities, entozoa trematoda, (Rud.), and those 

 whose body is elongated, continuous, or articulated, and the 

 head furnished with pits, with suckers, with one or four pro- 

 bosces, naked or armed, Ent. cestoidea, (Rud.) Both are de- 

 prived of an intestinal canal, and provided with ramified ova- 

 ries. This order comprehends in the human body the genera 

 Txnia, Disfoma, and Polystoma. 



853. The taenia have the body very much elongated, flat, 

 and articulated, and the head furnished with two or four little 

 suckers. Two species are found in man. 



The broad or unarmed taenia, T. lata, Bothriocephalus la- 

 tus, (Bremser, Rud.), has the head nearly square, two naked 

 pit-suckers, the head and the pits, which are marginal, oblong, 



