TAPEWORM, an intestinal worm, Twnia Mixon, in form somewhat resem bling tape. Its length is from 5 to 15 yards, and its breadth from two lines at the narrowest part to four or five at the other or broader extremity. At the nar row end is the head, which is terminated anteriorly by a central rostellum, sur rounded by a crown of small recurved hooks, and behind them four suctorial depressions; then follow an immense number of segments, each full of micro scopic ova. The segments are capable of being detached when mature, and re producing the parasite. There is no mouth; but nutrition appears to take place through the tissues of the animal, as alga= derive nourishment from the sea water in which they float. The digestive system consists of two tubes or lateral canals, extending from the anterior to the posterior end of the body, and a transverse canal at the summit of each joint.
The tapeworm lives in the small intes tines of man, affixing itself by its double circle of hooks. When the reproductive joints or proglottides become mature, they break off and are voided with the stools. They may get into water, or may be blown about with the wind, till some of them are at length swallowed by the pig, and produce a parasite called Cysti cercus cellulosx, which causes measles in the pig. When the measly pork is eaten by man, a tapeworm, the ordinary T. so num, appears in his intestines. This species mainly affects the poor, who are the chief pork-eaters. Called more fully the pork tapeworm. The beef tapeworm, T. mediocanellata, has no coronet of hooks on the head. The segments are
somewhat larger than in the ordinary tapeworm. It is 15 to 23 feet long. The cysticercus of this species forms measles in the ox, and is swallowed by man in eating beef. It chiefly affects the rich. The broad tapeworm, Bothriocephalus latus, is 25 feet long by nearly an inch broad, and chiefly affects the inhabitants of Switzerland, Russia and Poland.
The adult sexual Txmiadm live for the most part in birds and mammals, the lar val "bladder worms" or Cysticerci occur in both higher and lower animals.
Two Twniadx are in the adult sex ual state parasitic in man: Tmnia so /2:um, with the bladder worm stage in the pig; T. saginate or mediocanellata, with bladder worm in the ox; and some others, T. cucumerina, T. nana, T. flavomacula ta, and T. madagascariensis, occasionally occur. They infest the small intestine, and there also Bothriocephalus latus (larval in pike and burbot) may be found. Moreover twnioid bladder worms also occur in man, the most important be ing that of T. echinococcus, which lives as an adult tapeworm in the dog.
The presence of tapeworm in the small intestine need not be dangerous, but it is usually troublesome, giving rise to disturbances of digestion, colic-like pains, diarrhoea, or, on the contrary, constipation, besides less local effects, such as anemic and neurotic states. Of anthelmintics—which are intended to ex pel the parasite from the intestine—there is no lack in the pharrnacopceia,