PORK TAPEWORM 241 



likely to occur. The infrequence of these tapeworms in the 

 Philippines where the bladderworms are very common in hogs 

 is worthy of note. 



The adult Tcenia solium differs from the beef tapeworm chiefly 

 in the form of the scolex, which in addition to four suckers is 

 armed with a double row of hooks, arranged on a conical pro- 

 jection or " rostellum " at its apex (Fig. 82B). The worms are 

 usually of less length than beef tapeworms, seldom exceeding 

 from six to ten feet; they consist of about 800 or 900 segments. 

 The ripe proglottids (Fig. 84B) can in most cases be distinguished 

 from those of the beef tapeworm by their usually smaller size 

 and fewer branches of the uterus (compare Figs. 84A and B). 



The eggs, passed in the ripe proglottids with the faeces, develop 

 into bladderworms when eaten by hogs or cer- 

 tain other animals. The usual filthy way in 

 which hogs are housed and fed gives ample 

 opportunity for infection if the infested people 

 are at all careless in their personal habits, or 

 if privies are built so that they leak and the 

 hogs have access to the surrounding ground or 

 outflowing streams. Young pigs are especially 

 likely to become " measly " from eating tape- 

 worm eggs. 



As soon as the eggs reach the intestine FlG 89 Fragmen t 

 the six-hooked embryos are liberated from of measly pork. (After 

 the enclosing capsule and make their way 

 through the wall of the intestine, to be carried by bloodvessels 

 to the place where they are to develop. They may develop 

 in almost any or all of the muscles or organs of the hog's body, 

 but they especially favor the tongue, neck and shoulder muscles, 

 and, next in order, certain muscles of the hams. Sometimes 

 the bladderworms, technically known as Cysticercus cellulosce, be- 

 come so numerous as to occupy over one-half of the total volume 

 of a piece of flesh examined, i.e., several thousand to a pound. 

 They appear as small elliptical bladders from 6 to 18 mm. (one- 

 fourth to three-fourths of an inch) in length (Fig. 89). They 

 have a whitish spot at about the middle of the length, in the center 

 of which is the opening where the head is invaginated. 



Unlike the beef tapeworm, Tcenia solium can pass its bladder- 

 worm stage in a number of animals, namely hogs, man and dogs. 



