NEMATODES (ROUND WORMS) Ascaris lutsbricoides.—TIL's worm has a round body, whieh runs to a point at both end:s and is grayish red or salmon-red. Through the finely annular skin, shimmer the blood vessels of the abdomen and back, as well as a mass of twisted threads that represents the sexual organs. The mouth, which is at the anterior end of the body, has three lips with very fine teeth. The intestinal canal, which is in several sec tions and fills the whole body, ends at the hinder end of the body. In t.he male worm, which. is twenty- to twenty-five cm. long and three to four mna. thick, the hinder end of the body is usually slightly eurved in over the abdomen; and two small, hairy spicules project from the sexual opening, which is situated in front of the anus. The sexual opening of the female, which is from thirty to forty cm. long and over five min. thick, is at the hinder end of the anterior third of the body. According to Leuekart, the feinale produces from forty to sixty million eggs. The latter are .05 nom long; have three layers, of which the outer is rough, mulberry-like, and yellowish brown; and exist, in two forms (Fig. 39, a, b). According to Leuekart, the elongated oval eggs COMe from the virginal unfructified female. The embryos develop only from the eggs described under Fig. 39, a, within four to eight weeks—most successfully when they lie superficially' in moist earth, since they require oxygen. Lutz and Epstein have determined by animal experiments that round NVOTMS do not require any intermediate host. In the most manifold forms, particles of earth containing these embryo-like bodies may- enter into the human body. The closer the association of the individual with the earth, the more uncleanly the person is in his whole behavior, the more frequent will be infection with these parasites. T have found, for instance, round worms present in more than seventy per cent. of Italian longshoremen; in fifty-two per cent. of Bohemian children living in the country• and in only four per cent. of the children living in Prague.
The diagnosis of round worms is made by the laity when the worm is passed: but it is more exact to demonstrate the egg with the micro scope, which is possible with the smallest portions of feces. These
often adhere to the folds of the anus, and are easily obtained at any time by,' the introduction of a rectal souncl.
worms can give rise to general and local symptoms. Under the former may be mentioned loss of appe tite; abnormal appetite; salivation; itching of the nose; flitti»g abdominal pains, espe cially about the navel; nausea, when the stomach is empty; and diarrhica (enteritis verminosa). A series of nervous symptoms, arrhythmia of the pulse, ineepiality of the pupils, urticaria, cclampsia, ancl choreiform and epileptiform attacks have been observed by Lutz, Mosier, and Peiper. That so mani fold a symptom-complex can be due to the presence of round worms has been repeatedly throw» in doubt; but to-day it seems more intel ligible to us, since the investigations of Arthus ancl Chanson, Von Linstow, and Nuttal have shown that ascarides may produce a poison reacting violently upon the mucous membranes, as well as upon the central nervous system.
The following local symptoms cleserve special mention: palpable tumors, which have led to stenosis of the intestine, incarceration and volvulus, have been demonstrated to consist of a solid mass of ascarides. Every round worm may become dangerous by migration. In the stomach it will cause vomiting; in the lung, trachc•a, or bronchi, it will produce. different clegrees of suffocation, asphyxia, atelectasis, secondary pneu monia, and even death. Moreover, large numbers have been found in the biliary passages, usually of the smaller variety. There they have given rise to abscess of the liver and secondary fatal peritonitis. They have also been found as the _nucleus of gall-stones. Perforation of the healthy intestinal wall by the round worm seems very questionable, but ulcerative inflammation of the intestine may easily give rise to abscesses from which the ascarides migrate to other parts of the body.