. Fig. 47. — Head, Greatly En- larged. Fig. 48.—Proglottid of Hymenolepis. This preparation I owe to the kindness of Pro- fessor W. Müller of Greifswald. The most familiar of the bothriocephali is the Bothrlocephalus latus, Bremser, 1819. This broad bothriocephalic, called also the pit-head, measures 5-9 meters and is the longest tape-worm of man. The club-shaped head shows on its lateral border on each side an elongated, slit-like pit. The individual pro- glottides, 3,000 to 4,200 in number, are remarkably broad in proportion to their length. A grayish-blue centerpiece of rosette-like form bo
. Fig. 47. — Head, Greatly En- larged. Fig. 48.—Proglottid of Hymenolepis. This preparation I owe to the kindness of Pro- fessor W. Müller of Greifswald. The most familiar of the bothriocephali is the Bothrlocephalus latus, Bremser, 1819. This broad bothriocephalic, called also the pit-head, measures 5-9 meters and is the longest tape-worm of man. The club-shaped head shows on its lateral border on each side an elongated, slit-like pit. The individual pro- glottides, 3,000 to 4,200 in number, are remarkably broad in proportion to their length. A grayish-blue centerpiece of rosette-like form bordered by two narrower bands is distinctly visible upon both surfaces. On the ventral surface are the male sexual opening and the mouth of the vagina. The mature ova are ovoid in form and surrounded by a brownish shell with a lid. The ova are rarely found in the last mature segments of the chain. Large numbers of proglottides are often expelled at once. They are voided with the feces, having been previously discharged from the uterus. If the ova reach the water, ciliated embryos develop within them, which slip from the shell of the ova and float for some time in the water. The ciliated covering perhaps seeks the intermediary host, which, as we learn from Braun's brilliant investi- gations, was found to be the pike (esox lucius), the burbot (lota vulgaris), the perch (perca fluviatilis), the trutta vulgaris and lacustris, the thymallus vulgaris, and the onchorhynchus Perryi. It is still undecided whether this list exhausts the number of intermediate hosts. The young of the bothriocephalus, plerocercoides, dwell encapsulated in various parts of the intestines and of the musculature, and usually in large numbers. Bothriocephali have been cultivated by feeding experiments with plero- cercoides in the dog, the cat, and also in man. The transmission of the parasite undoubtedly occurs by means of fish. It takes place frequently in infected districts where fish are eaten raw, half
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectblood, booksubjectpoi
