10 



conditions they give rise to ; and the best mode of 

 treatment. 



Tcenia solium (PI. I. fig. 1). Description. These 

 cestoids are flat and narrow, composed of articula- 

 tions, slender, and but slightly flattened anteriorly ; 

 becoming broad and expanded as they recede from 

 the head, and estimated of various lengths ; 4 or 

 5 metres (12 to 15 feet), (Moquin-Tandon), never 

 exceeding 24 feet (Weinland, from Diesing), from 



9 to 35 feet (Aitken), and from 10 feet upwards 

 (Owen) ; having, in this latter case, been found to 

 extend from the pylorus to within 7 inches of the 

 anus. The average length may be stated as from 



10 to 12 feet. They are covered with a soft, nearly 

 white integument, in which are scattered little granu- 

 lar masses, at one time supposed to be eggs, now 

 proven to be carbonate of lime (Weinland et alii). 



Head (PI. I. fig. 2, B). The head is of the size 

 of a pin's head, and frequently colored with a black 

 pigment ; it is hemispherical or globate in form, and 

 provided at the sides with four rounded nipples, diago- 

 nally placed ; in the centre of each one is seen a cir- 

 cular disc which is imperforate (PI. I. fig. 2, D ; 

 Kuchenmeister). Anteriorly, and in the midst of 

 these suckers, is noticed a convex protuberance, 

 which is not perforated, and which is surrounded by 

 a double row of hooks (PL I. fig. 2, E), from 22 to 30 

 in number (Moquin-Tandon). These little hooks are 

 siliceous or cornuate in nature, and are composed of 

 three portions, viz., the handle or root (PI. I. fig. 2, 

 C, ) ; the hook proper (PI. I. fig. 2, C, y), which is 



