. A manual of zoology. Zoology. IV. NEMERTINA cellulose of T. solium, found in man, more frequent and of more importance is the cysticercus of Tamia echinococcus (fig. 232), which lives as an adult in the dog, and is easily overlooked on account of its size. It is at most i inch long and consists of a scolex and three or four proglottids. When the eggs are taken into the human stomach, as may easily happen by stroking and kissing infected dogs, the embryos are set free and wander into liver, lungs, brain, or other organs and produce here tumors which, in the case of the liver, may weigh t
. A manual of zoology. Zoology. IV. NEMERTINA cellulose of T. solium, found in man, more frequent and of more importance is the cysticercus of Tamia echinococcus (fig. 232), which lives as an adult in the dog, and is easily overlooked on account of its size. It is at most i inch long and consists of a scolex and three or four proglottids. When the eggs are taken into the human stomach, as may easily happen by stroking and kissing infected dogs, the embryos are set free and wander into liver, lungs, brain, or other organs and produce here tumors which, in the case of the liver, may weigh ten or even thirty pounds. This extraordinarv size is explained by the formation of daughter bladders (echinococcus) described Fig. 234.—Heads and proglottids of three tapeworms of man. Left, Tmtia sagi- nata; middle, T. solium; right, Bothriocephalus la/us, flat and side view of head. The heads enlarged about six times, the proglottids about ih (after Leuckart, Braun, and Schauinsland). Common Tccnix of domestic animals are in the horse Anoplocephala plicata (4 to 30 inches), A. perfoliata [^ to 3 inches), A. mamillana (J to 2 inches); in ruminants, Moniezia,''' in the dog, Tania marginaia* (cysticercus in sheep and swine), T. serrata* (cysticercus in rabbits), T. echinococcus (above), T. ccenurus (cysticercus in brain of sheep, causing the disease called 'staggers'), DipvUdium cticumerina* (most common, larva in the flea and dog-louse); in the cat, Tccnia crassicollis'^' (cysticercus in mice). Several species occur in domestic birds, one {Drepanidotcenia infimdibuUformis*), causing epidemics among chickens. Others in ducks and geese. Class IV. Nemertini. Most nemerteans are of appreciable size, some reaching a length of a yard or more (Lineus loiigissimus 90 feet !), and yet they are so contractile that our Cerehratulus lacteus, which can extend itself to fifteen feet, can retract to two. Nemerteans are rare in fresh w^ater or moist earth, but are most abundant in th
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1912
