CESTODA 87 



graphic des Helminthes ou des vers parasites de 1'homme " 

 (Vers Cestoides, pi. ii), Louvain, 1860. Welch, F. H., "Obser- 

 vations on the Anatomy of Ttenia mediocanellata" ' Quart. 

 Journ. of Microsc. Science,' vol. xv, 1875. Zenlter, in ( S. B. 

 Soc./ Erlang. iv, s. 71. Zurn, ' Zoopathologische und physiol. 

 Untersuchungen,' 1872. 



Ttenia solium, Linneus. This cestode was formerly known 

 as the common tapeworm, but in England it is of far less fre- 

 quent occurrence than the beef tapeworm. In contradistinc- 

 tion it is best to speak of it as the pork tapeworm. Though 

 only one specimen is usually present, the bearer may entertain 

 several worms of this species at one and the same time. The 

 parasite has been known to science from the earliest times, 

 though possibly not earlier than the measles, or Cysticerci, from 

 which it originates. Hippocrates, Pliny, and Aristotle describe 

 the full-grown worm ; and, in regard to the larvae, some have 

 gone so far as to express their belief that the prohibition of 

 swine's flesh as food amongst the Jews and other Oriental 

 people, was dictated by sanitary considerations. Weinland has 

 suggested that the Mosaic commandment not to eat pork may 

 have originated in an old popular notion " of the fact that tape- 

 worm sometimes comes from this food." Weinland' s hypo- 

 thesis is probably correct, for if one supposes Moses to have 

 been supernaturally informed that pork would produce tape- 

 worm disease, one naturally asks why veal and beef should not 

 also have been prohibited, seeing that these meats also fre- 

 quently harbour tapeworm larvse. 



A perfect pork tapeworm presents itself to the eye of the 

 observer as a long, soft, white, jointed strobile, which, when 

 alive, elongates and contracts itself with facility. Though 

 commonly spoken of as a single creature, it is a compound of 

 many individuals. These are variously called " cucurbitini," 

 " zooids," " proglottides," " segments," " links/' or " joints." 

 When fully grown the segments are capable of detaching them- 

 selves and of enjoying a free and independent existence. Very 

 annoying it is to the human bearer to be continually reminded 

 of his unwelcome " guests " as they seek to quit his interior. 



The head of Tania solium is seldom seen in anatomical 

 museums, although the evacuation of pork tapeworms is not of 

 rare occurrence. Placed under the microscope, the head dis- 

 plays a quantity of dark, almost black, pigment granules, 

 which are abundant at the base of the rostellum and in the 



