The trichina spiralis was discovered by Paget,3 but its pathological importance was first recognized by Zenker.4 This parasite is observed in two forms, the trichina of the intestine and the trichina of the muscles (see Plate I.).

Trichina Spiralis

Plate I. Trichina Spiralis (Hubert.)

The trichina reaches the stomach through the ingestion of pork containing encapsulated trichinae. In the stomach the capsule opens about three to four hours after the ingestion of the meat and the embryos rapidly develop. At the end of thirty to forty hours fructification of the young parasites takes place.

1 Mosler: "Darminfusion." Real-Encyclopadie der gesammten Heil-kunde, Bd. v.

2 Peiper: "Helminthen." Real-Encyclopedic der gesammten Heil-kundc, Bd. ix.

3 Paget, cited after Huber: "Twentieth Century Practice of Medicine, " vol. viii., p. 608.

4 Zenker: Deutsches Arch, fur klin. Medicin, i., 1866.

Explanation Of Plate I

Fig. 1. - Muscle Trichina Enclosed in a Fully Developed Cyst. X 240. Cy, cyst; Bg, connective-tissue envelope; Fk, fat globules.

Fig. 2. - The Same Removed from the Cyst. X 400. Oe, Cesophagus Zk, cell bodies; L, sidelines; Ov, ovary; Ch.D, chyle duct.

Fig. 3. - Part of the Ovary. X 600. Is readily distinguished from the testicle by the varying size of the germ cells.

Fig. 4. - Male Intestinal Trichina. X 100. T, Testicle; d ej, ejaculatory duct; Zk, cell bodies.

Fig. 5. - Female Intestinal Trichina. X 90. Ov, ovary; E, embryos; Oe, genital opening from which the embryos escape.

Fig. 6. - Free Embryo, x 400. 0, mouth; A, anus.

Fig. 7.-Embryo About Three Days After Having Entered the Muscle Fibre. MF, normal muscle fibre.

Fig. 8. Muscle Trichina. About Six Days Old, in the Greatly Swollen Sarcolemma Sheath Traversed by Capillary Vessels. Cap.

Fig. 9. - Muscle Trichina, Four Weeks Old, Enclosed in a Capsule, Cy .1. within the sarcolemma sheath. Sk. BK, connective-t issue capsule in processor active growth; k, nuclei; MF. contents of the sarcolemma sheath at each pole of the capsule.

Fig. 10. - Muscle Trichina with Calcined Capsule. Fk, Fat globules.

The intestinal trichinae are visible with the naked eve, the females being 3 to 4 mm. long and the males half this size. The caudal extremity is thicker than the head end. Five days after fecundation the females give birth to living young ones. The young brood wanders directly from the intestine of the host into his muscles. Here they further develop. In this condition they give rise to a febrile disease accompanied by severe muscular symptoms which may lead to death. Sometimes the trichinae become encapsulated. The symptoms vary according to the number of worms which have been ingested. Gastro-intestinal disturbances usually appear on the second or third day after the ingestion of the contaminated meat. Vomiting, diarrhoea, colic often appear.

The disease known as trichinosis, which depends upon the further development of the young embryos in the muscles of the host, is not within the scope of this book, and we refer to this parasite only as far as its occurrence in the intestines is concerned. With regard to prophylaxis pork should never be eaten raw. The treatment after the ingestion of trichinous meat consists in the employment of lavage of the stomach, if the physician is called early enough after the meal. In addition a vermifuge and cathartic remedy should be given immediately.