but neither oxen nor sheep. The pigs become trichinous from eating offal,1 man becomes trichinous from eating pork or bacon or ham derived from a trichinous pig.

The male worm is only inch when fully developed, the female is longer, the length being inch; the body is rounded and thread-like, the head is narrow, finely pointed, unarmed, with a simple central small mouth opening; the posterior extremity of the male is furnished with a bilobal caudal appendage, the anal aperture being situated between these divergent appendages; the penis consists of a single spicula cleft above, so as to assume a V-shaped outline. The female has the genital outlet placed far forward, at about the end of the first fifth of the long diameter of the body; the eggs measure in their long diameter 17 inch, these are hatched in the body of the parent; the reproduction is therefore viviparous.

The females contain mostly from 500 to 600 eggs. The new-| born young being hatched, commence their wandering. They penetrate the wall of the intestines and pass into the muscles, proceeding in the course of the intermuscular connective tissue. It is specially those muscles which are nearest to the cavity of the abdomen in which the majority of the trichina are found. It takes about fourteen days for the embryos to attain the full growth. Soon after the introduction of the parasite into the muscle, the infested muscular bundle loses its structure, and at the spot where the worm coils itself up a lemon-shaped or globular little cyst is developed. In this cyst there may be from one to three trichinæ. The cyst often becomes calcified.

During this migration the individual affected suffers from pains in the limbs, and often swelling about the joints with fever; there is also often diarrhoea and peritonitis. The disease is likely to be confused with rheumatism, rheumatic fever, tuberculosis, enteric fever, and pyæmia. If a considerable quantity of trichinous meat is consumed, the embryo may be produced in prodigious numbers and the results are then likely to be fatal. In 1863, out of 103 persons who ate sausages made of an affected pig, at Hettstadt, eighty-three died from trichinosis, and there are several similar cases on record. In 1873, 250 persons suffered from trichinosis at Magdeburg, Germany. Many died and most were seriously ill.

1 It has been suggested that rats are also a source of trichinæ.

Bits of muscle removed by a trocar from some of the sufferers and weighing about a gramme were found to contain as many as 800 trichinæ. The symptoms produced are not usually immediate but follow after from five to six days.

It is not known how many pigs in this country are affected with trichinosis.

In America the Massachusetts State Board of Health have from time to time published the results of their supervision over the meat supply; thus in 1879 Dr. F. S. Billings examined 2,701 hogs, 154, or 5.7 per cent. were trichinous; in 1881 6,068 hogs were examined, 191 or 3.15 per cent. were trichinous. Professor E. L. Mark gives a return of careful examination of hogs raised near Boston, from which it appears during the period 1883-1888, out of 3,064 hogs 394 or 12.86 per cent. were found trichinous.

(462) Examination of Meat for Trichino.

The best part to search for trichinæ is the diaphragm, 25 per cent. of the total worms being found in that large muscle; after the diaphragm come the muscles of the shoulder and those of the loins but in a hog thoroughly infested, there is no muscle in which they may not be found, provided trouble is taken; the muscles of the back are those least affected.

A low power is only necessary (30 to 40 diameters), little bits of the muscle are teased out with needles and placed, after flattening out by the cover-glass, and adding a little glycerin, in the field of the microscope. Non-encysted trichinæ may be readily discovered in this way, on the other hand those that are encysted require special treatment; if the cyst is calcified a little hydrochloric acid will soon clear it up, the muscular substance may also be disintegrated by potash, which will not affect the cyst, but on the contrary render it more visible. By adopting such processes there should be no difficulty in identifying the worm if present. Plate VII. represents (natural size) a specimen of muscle from the human subject containing encysted trichina (Royal College of Surgeons' Museum). Professor Mark1 takes nine slips of meat from the pillar of the diaphragm, and if no trichinæ is found in any one of

1 Twentieth Report of the Massach. State Board of Health.

the nine samples the hog is passed as non-trichinous. He states that in several instances trichinæ were only detected in the eighth or ninth slip examined.

(463) Vitality of Trichina.

Trichine when encysted, have considerable tenacity of life. Müller found, for example, that trichinous flesh steeped in strong brine for 8-10 days was still able to infect rabbits. Trichina will withstand drying in the air or sun, and will live in putrified meat, but meat which has been boiled or roasted thoroughly experiment has shown is perfectly safe, but as trichinæ are not killed by a temperature of 122° F., the meat may still infect if the interior of the joint has not been brought to a sufficiently high temperature.

(464) Glanders and Farcy.

Horseflesh derived from a glandered horse is decidedly unfit for human food, although sold under its proper appellation "horseflesh." Glanders is a micro-parasitic disease affecting the horse, and which may be transmitted to man and cattle by inoculation. It is associated with a special bacillus the size of the tubercle bacillus. The disease is especially characterized by nodules and ulcers in the mucous membrane of the nose, the lymphatics also become affected, and nodules form in the internal organs, that is the lung, spleen, and liver.

(465) Variola of Sheep.

Variola or small-pox of sheep is an eruptive malady analogous but not identical with the small-pox of the human subject. There is a definite eruption which proceeds from red points to nodules, and then becomes pustular, the pustules ultimately break, then scab, the scab after a time becomes detached, leaving a cicatrix. The changes are chiefly in the skin, but also the mucous membranes of the nose and eyes are affected, the lymphatic glands are also inflamed. The flesh looks healthy, and apart from the skin the meat might be sold without detection. Variolous sheep are said to have been largely eaten in Paris at the time of the last siege of that city without injury. Nevertheless the meat of such animals should most decidedly be condemned.