As a prophylactic measure against infection the avoidance of too intimate association with dogs is especially to be recommended.
In concluding the chapter on Tænia echinococcus, as a prophylactic against this and other parasites Cobbold gives the advice that "all entozoa which are not preserved for scientific investigation or experiment should be destroyed by fire when practicable, and under no circumstances whatever should they be thrown aside as harmless refuse."
TÆNIA ACANTHOTRIAS.
Larval condition: Cysticercus acanthotrias.
This species has been but once observed, and only in the larval condition or that of the scolex, which was first described by Weinland. About a dozen specimens were found by Jefferies Wyman of Boston in the body of a woman of Virginia who died of phthisis. They were situated in the connective tissue beneath the skin and in the muscles, except one, which was attached to the dura mater. The scolex is distinguishable from that of the other human tape-worms in possessing a triple circle of hooks. The mature form of the worm remains unknown.
The Trematodes, or Fluke-worms.
The trematodes or fluke-worms, though allied to the tape-worms, differ in many important characters. In the mature condition, like the latter, they are solid worms or are devoid of a body cavity or coelum, and are with rare exceptions hermaphroditic. They are, however, never compound, but simple or consist of single individuals, and are provided with a mouth and alimentary canal, but this is closed or is without an anal aperture. They have a water vascular system, communicating with the exterior by a pore at the posterior extremity of the body. They are commonly of flat, elliptical shape, with a sucker-like mouth at the fore end, and with a second sucker situated ventrally near the middle.
The fluke-worms are remarkable for their successive transformations and course of life, and, like the tape-worms, they pass the different stages of their existence in different animals. A number of species have been described as infesting man, but most of them are, fortunately, of rare occurrence.
DISTOMUM HEPATICUM.—SYNONYMS: Fasciola hepatica; Liver-fluke.