564 THE MICROSCOPE. 



terminal prominence. The embryo passes through a 

 similar course of development to the Trematoda ; viz. 

 four forms or changes : but the embryo itself is very 

 peculiar, consisting of an oval non-ciliated mass, provided 

 upon one face with six hooks, three upon each side of the 

 middle line. The Tceniadce are /ound in many other 

 situations besides the alimentary canal : the eye, the brain, 

 the muscular tissues, the liver, &c. ; the following cystic 

 worms are included in this genera, Cysticercus Anthoce- 

 phalus, Ccenurus, and T. Echinococcus. Plate IV. No. 100, 

 this figure shows an entire and full-grown Tcenia with 

 rostellum and suckers, and then three succeeding segments, 

 the last of which contains the ova, &c. The water-vascular 

 system is represented coloured with carmine. This para- 

 site infests the human body more frequently than other 

 varieties. This accurately-drawn figure is copied from 

 Cobbold. 



Yon Siebold, Leuckart, and others, have shown, by many 

 interesting experiments, such as feeding puppies with Cys- 

 ticercus pisiformis, that in the course of a few weeks these 

 entozoa are transformed into fully formed Tcenia serrata , 

 again, rabbits fed with the embryo of the Tcenia, the 

 embryo bore their way, by means of hooks, through the 

 walls of the intestine, until they reach some blood-vessel : 

 by the current of blood they are carried into the liver, 

 and here Leuckart has traced their further development. 

 The embryos grow to the 1-1 6th of an inch in length, and 

 become elongated, so as almost to resemble an Ascarid in 

 form ; they then make their way to the surface of the liver, 

 and pass out into the peritoneal cavity. 



In like manner, Cysticercus fasciolaris is rapidly developed 

 within the liver of white mice ; Cysticercus cellulosce seen 

 in the muscles of the pig fed with the Tcenia solium, pro- 

 duces the diseased state of pork familiarly known as 

 " measly pork." If a lamb is the subject of the feeding 

 experiment with Tcenia serrata, the final transformation 

 will be very different ; within a fortnight, symptoms of 'a 

 disease known as " staggers" are manifested, -and in the 

 course of a few weeks, the Coenurus cerebralis will be found 

 transformed and developed within the brain. Yon Siebold 

 pointed out the bearing of this fact upon the important 



