=Taenia Saginata.=—This is derived from beef, and is much longer and larger than the taenia solium. It is from five to six yards in length; the head is over two millimeters in breadth, is square shaped, and has four large sucking discs, without hooklets; hence it is called the unarmed tape-worm, in contra-distinction to the hooked variety. The segments are thicker and the ova larger, and they are passed and ingested in the same manner as the taenia solium. =Bothriocephalus Latus.=—This is found especially in Europe and is very long, measuring from eight to ten yards; it is derived from fish, is not provided with hooklets, but has two lateral grooves. The segments are short and wide, the sexual organs being on the narrow side of the segment. =Etiology.=—Unhealthy condition of the stomach and intestines is the predisposing, and uncleanliness an important, factor in the occurrence of tape-worm. Those eating imperfectly cooked beef, pork, fish or other meats, and those handling fresh meats, are liable to be affected with tape-worm. When the ovum is taken into the stomach the capsule is dissolved and the embryo passes into the small intestines, fastening itself into the mucous membrane, by its hooklets and suckers and grooves. =Symptoms.=—Tape-worms occur in the human being at all ages. Oftentimes symptoms are absent, the expulsion of segments being noticed and thus the worms accidentally discovered. The tape-worm is seldom dangerous, but if a worm is known to exist it is always a source of considerable anxiety on the part of the patient. Severe anemia may result and be wrongly diagnosed. There are dyspeptic symptoms, colicky pains, nausea and occasionally diarrhea. The appetite is variable, sometimes ravenous. This condition is followed by loss of flesh and various reflex phenomena, as vertigo, headache, convulsions, palpitation, choreic movements, itching of the nose and anus, paralysis, and rarely, insanity. In addition to these symptoms there may be a wrinkled countenance, sensation of a cold stream winding itself toward the back immediately after a meal, pain in various parts of the body and ringing in the ears. The decisive diagnostic symptom is to find segments of the worm in the stools. =Diagnosis.=—Discovery of the ova or segments in the passages of the bowels is the only proof of the presence of a tape-worm. =Prognosis.=—Favorable in all cases. =Treatment.=—Prophylactic treatment is necessary. Meats should be thoroughly cooked so that the larvæ will be destroyed; and all segments of tape-worms passed in the stools should be burned—by no means should they be thrown outside or in the water-closet.