230 ECHINOCOCCUS HOMINIS. 



This species is found in the gall-bladder, and Dr. Bremser supposes 

 also in the human liver. It is very common in sheep, generally found 

 adhering by a pore at the extremity and another at the end of the 

 abdomen, and is said to cause the disease called the rot in these 

 animals. It is three or four lines in length, of an oblong ovate shape, 

 obtuse at each extremity, and of a dirty whitish or brown colour. 



ECHINOCOCCUS HOMINIS. 



The Hydatid. 



Pl. XXIX. A. fig. 4. 



Order Cystica, ltudolphi. 



Gen. Char. Body ovate, vesicular, containing a fluid 

 which is generally transparent, inclosed by a capsule ; 

 head furnished with retractile hooks, or crotchets, and 

 suckers as in the tamia. 



Polycephahis liomiuis ; Joerdens, Helminth, t. 7, f. 21, 22 L'Ecliinocoqtic de 

 riiomme, Lamar. An. sans. Vert. iii. p. 157. E. hominu; Rudot. Enloz. 

 p. 183,551. 



" The Hydatid," says Mr. Rhind, "is a spherical body, consisting 

 of one and sometimes of two membranes, enclosing a fluid most 

 commonly limpid and transparent, but which is sometimes found 

 of a tough, hard, and opaque consistence. On the inner coat of 

 the membrane are attached a number of small granular bodies, 

 which are called the echinococci. Rudolphi divides the hydatids 

 into viventes and non viventes. He denies the vitality of the 

 hydatid, properly so called, and supposes that the small granular 

 bodies, or echinococci only, which cover the internal surface of 

 the membrane, are endowed with life. Bremser, on the other 

 hand, is of opinion, that the vesicle is a distinct animal, and that 

 the small granulations on its internal surface are hydatids in 

 miniature, which, gradually enlarging, and detaching themselves 

 from the parent covering, become in their turn independent ani- 



