OUR UNBIDDEN GUESTS. Si 



first host. Man, in other words, obtains his common 

 tapeworm guest from the pig. When this animal 

 swallows the egg of a tapeworm, the young worm 

 bursts through the egg-case and bores its way to the 

 pig's muscles. If the porker is affected by numerous 

 embryos, that is, if it has swallowed a large number 

 of eggs, it will become feverish and ill, and it will 

 then be said to have developed "measles." The 

 i( measles" of the pig are the visitations of young 

 tapeworms. In the muscles of the pig, then, these 

 young worms rest. J'y suis; fy rcste, is decidedly 

 the motto of the young worm. It developes a little 

 head and neck, and it also, by way of a tail, produces 

 a little bladder or bag. Before naturalists knew its 

 true nature, it was regarded as a special kind of para- 

 site, and was named a " cystic worm." 



If the pig dies a natural death and is respectably 

 interred, or if the pig should live long enough, these 

 youthful tapeworms will respectively perish, or will 

 degenerate and disappear from the tissues of the aged 

 porker. But assuming that the usual Nemesis of the 

 pig race overtakes the animal, then, in the form of 

 pork, it will gladden the heart of certain members 

 of the human race. Now, let us suppose that a man 

 eats a portion of the ' ' measly pork." Let us further 

 suppose that the pork has been imperfectly cooked; 

 then comes tho "tide of fortune" to the young worms. 

 For when the young worm has been eaten by the man, 

 the bladder-tail drops off. Each little head and neck 

 finding itself in the human stomach, recognises its 



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