Six to ten feet long, with seven to eight hundred joints, and a circlet of hooks (Fig. 136), lives in the human intestine. Several of its sexually mature joints are commonly pinched off at a time, and if these are picked up from a field or dung-heap by a pig, the contained eggs develop into “pork measles” (_Cysticercus_, Fig. 140), which are especially abundant in the connective tissue between the muscles, and make the meat “measly.” They may also occur in the connective tissue of other parts (fat, brain, spinal cord). Young pigs not more than six months old are most in danger of becoming measly. A tolerably large number of measles can be borne very well, but if very abundant they cause emaciation, weakness, lameness, and poverty of blood. The flesh of an animal badly infested with measles may be pale, watery, or even greasy, while pork not so much diseased may seem all right, though it is really unfit for food, since if eaten in an insufficiently cooked state by human beings it would produce tapeworms. The measles are most abundant in the muscles of the breast and neck, and next to them in those of the hams and shoulders. From twelve to twenty thousand measles may be present in a single pig. The =Unarmed Tapeworm of Man= (_Tænia saginata_) lives in the intestine of man, and, as a bladder-worm (_Cysticercus_), in the connective tissue of the muscles of the ox (and especially in the calf). It is from twelve to twenty feet, with as many as a thousand joints, but does not possess a circlet of hooks. The joints generally leave the intestine one by one, and creep on to grass and herbs, where they burst, so that the eggs are set free, and therefore get widely distributed. The ox scarcely ever takes in several joints of _Tænia saginata_, and consequently only a certain number of eggs. Beef never, therefore, contains so many measles as pork, and there is not a special measle disease of oxen. As, however, the eggs of _Tænia saginata_ are more widely distributed, calves and oxen are more frequently infected with bladder-worms than is the case with swine. The =Cœnurus Tapeworm of the Dog= (_Tænia cœnurus_)