AFFECTIONS OF THE INTESTINAL CANAL. 



among the numerous remedies administered, there are always laxatives 

 and opium, and their effect seems to depend on these remedies. 



CHAPTER IX. 



WOBMS IN THE INTESTINAL CANAL HELHINTHIASIS. 



THE worms most frequently found in the human intestines are tho 

 taenia solium, the taenia mediocanellata, the bothriocephalus latus, the 

 ascaris lumbricoides, the oxyuris vermicularis, and the trichocephalus 

 dispar. 



The tcenia solium, the long tape-worm or chain-worm, is from ten 

 to twenty feet long, yellowish-white, thin and round at its anterior 

 end, and broader and flatter posteriorly. It is divided into head, neck, 

 and body, the latter consisting of many hundreds of links. The head 

 forms a blunt, square, bulbous enlargement ; it consists of a slightly- 

 prominent conical snout, which is surrounded by a double row of hooks, 

 and farther back by four round suckers symmetrically placed. The 

 neck is very slender and about half an inch long. Then come the 

 youngest links, which are scarcely quarter of a line broad, while the 

 terminal and at the same time the oldest links may be half an inch 

 wide or even wider. The individual links, which in shape remind us 

 of a pumpkin-seed with the ends cut off, have different structure 

 according to their age. The younger ones have a simple, slightly 

 brownish-yellow median canal, with short lateral off-shoots, the first 

 indications of sexual organs. The older links have a small prominence 

 at the edge, sometimes on one side, sometimes on the other, but not 

 regularly alternating, from which the sickle-shaped penis projects, and 

 into which the tortuous seminiferous tubes and the oviducts empty. 

 The interior of the older links is almost wholly occupied by a uterus 

 branching out to both sides or by the ovary. In the oldest links, the 

 latter is filled with eggs, and the small embryos with their six small 

 hooks may often be distinctly recognized. Vessels start from a vas- 

 cular ring within the head, and run down the side of the links ; accord- 

 ing to some observers, these communicate by transverse canals. Thus 

 far no other organs have been observed in the taenia. 



The taenia solium inhabits the small intestine, but may enter the 

 large. There is usually only one, but there may be two or more, 

 in one person. Taenia solium occurs in Europe, America, Asia, and 

 Africa ; and, very curiously, it is not found, except in Switzerland, in 

 countries where the bothriocephalus latus occurs. 



Until within a few years, the tcenia mediocanellata has been con- 

 founded with the taenia solium, and in fact its individual links are ven 



