Trichina, a genus of Nematode worms, containing several species, of which Trichina spiralis is the best known. This lives in the muscles of the pig and rabbit, usually occurring in small numbers, and each worm being contained in a small cyst from about a fiftieth to a seventieth of an inch in length. The worm lies coiled up in the cyst. In this condition the worm is immature, the sexual organs being undeveloped. If meat containing living Trichinae is eaten, these develop in about forty-eight hours into mature sexual forms. The males area bout one-sixteenth of an inch long and have two small processes on the tail; the females are nearly twice as large. At the end of a week the females begin to hatch broods of embryos. These are cylindrical in shape, and bore through walls of the intestine, into the muscles of the body, where they become encysted. They produce the disease known as "Trichinosis," which is common in Germany and America, but rare in England. Nothing can be done to the Trichinae that have got into the tissues, but the worms in the intestine can be killed off by castor oil, calomel, etc. The chief symptoms of this malady are fever with digestive disturbance, and muscular swelling and pain; dropsy is often present, and hoarseness and difficulty of breathing sometimes occur. The mortality is generally high and death may occur at the end of three or four weeks.