2.- Various Forms of Tapeworms. A, Taenia echinococcus; X 12 (from Leuckart).
Taenia echinococcus has only three, Echinobothrium four, Bothriocephalus three thousand.
Man himself, as well as other mammals, is the intermediate host of the dangerous parasite, Taenia echinococcus, in countries where cleanliness is neglected; the pig is the host of Taenia solium, and other cases may be seen from the table at the end of this article.
D, stages in the development of the broodcapsules in Echinococcus: a, the thickening of the parenchyma of the bladder; b, subsequent formation of a cavity in it; c, development of the suckers; d, a capsule with one head inverted into its cavity; e, a capsule with two heads; X 90.
B, Echinococcus, showing at a and b the formation of secondary bladders, which at c are forming scolices.
Echinococcifer echinococcus, a minute form with only three to five proglottides, in dog, wolf, jackal.
The embryo of the taenia echinococcus finds its way from the stomach or intestine into a vein passing to the liver, and, settling itself in the liver, causes so much disturbance there that a capsule of inflammatory material forms around it.