a closely related organism to be the causative agent (C. B. XXIV, 577).

Bacillus ædematis maligni. Koch.

(Plate 46.)

Synonyms.-Vibrion septique of the French. Bacillus of malignant edema.

Literature.-Koch (Mitt. a. d. Gesundheitsamt 1, 53); Kitasato (Z. H. vi, 111); Jensen and Sand (Deut. Zeit. f. Tiermed., XIII); Penzo (C. B. x, 822); Horne (C. B. XIX, 77); Besson (A. P. ix, 179).

Microscopically. - Vigorous rods, like tetanus and symptomatic anthrax, but with a greater tendency (of diagnostic value!), especially in the cadaver, to grow into long threads. Active motion is due to rather numerous (20 to 40) peritrichous flagella, but it is only present in the short forms, the long threads being usually scarcely at all motile. In the short rods spores form at the middle sometimes, at the end sometimes, and they are oval or spherical. Our cultures were not stained by Gram's method, and most authors have obtained the same result. In cultures we found the Bac. cedematis maligni to be indistinguishable from the bacillus of symptomatic anthrax, as shown in Plate 46; we have not placed more illustrations in this plate because they would be only repetitions of those of symptomatic anthrax. We found only that the growth was somewhat more scanty than that of symptomatic anthrax, and the vitality of the cultures of shorter duration. importance is the universally demonstrated inability to sour milk (to break up milk-sugar); the milk is coagulated, with amphoteric reaction. Abundant formation of alkali by the organism reveals itself by darkening of the brain nutrient media. The chemical products have been much studied, and are essentially all enumerated on page 331. Also, in addition, in media containing grape-sugar there occur ethyl alcohol and inactive lactic acid (Kerry). A mixed culture of the Micr. acidi paralactici Nencki and the Bac. œd. maligni produces butyl alcohol abundantly, but neither variety alone can do it (Nencki, C. B. XI,

Of

Distribution. Very widely distributed in soil, contaminated water, hay dust, etc. The inoculation of animals (best guinea-pigs) with samples of soil very readily produces malignant edema (still more often than tetanus). According to Horne, the most various septic diseases of domestic animals are occasionally produced by this bacillus. The section reveals, especially at the point of infection, a marked, bloody, gelatinous, often wide-spreading edema, with enlargement of the spleen.

Animal inoculations are made in practice by the subcutaneous injection of anaerobic bouillon cultures, most conveniently with not too small quantities of the edematous fluid from dead animals, or by the introduction of the infectious material into a deep cutaneous pocket. Spores without toxins infect with difficulty or not at all. The administration of toxins or the negatively chemotactic lactic acid increases the danger of infection very much (Besson, A. P. IX, 179). Also, according to Penzo, as in tetanus, the toxins formed in vitro are of the greatest importance in the outcome of the animal experiment; small doses of the pure culture he found to be without effect. Very small quantities of very virulent cultures suffice. Of the experimental animals, guinea-pigs and mice, and, in distinction to symptomatic anthrax, also rabbits, are very susceptible, and, besides, cattle, sheep, goats, horses, and pigeons.

The symptoms of the experimental disease in guineapigs correspond very beautifully with those in the spontaneous disease. Also in the case of animals dying from other causes, especially in warm places, bacilli may be found in the blood (having wandered from the intestinal canal) which are identical with or very similar to those of malignant edema; therefore care must be taken in the consideration of cadavers which are not fresh!

In the blood of recently dead animals the bacilli are not usually found microscopically (but may usually be demonstrated by cultures without difficulty), and very soon after death they spread everywhere, especially in the form of long threads. In the mouse, which is especially susceptible, there is also marked multiplication in the blood.

Infection occurs especially readily if the wound is contused or, as is very often the case in natural infection, other bacteria, hardly injurious of themselves, are simultaneously inoculated; for example, Bact. vulgare or Bact. prodigiosum.

Brief Differential Diagnosis.

See the key, on page 306, for the differential diagnosis between Bac. oedematis maligni and Bac. Chauvoi. For completing the diagnosis the following are to be carried out:

1. Examination of a fresh preparation for motility.

2. Two smear preparations are made from the edematous fluid or muscle juice and stained with fuchsin and by Gram's method.

3. Experiments upon guinea-pigs, and the examination of the phlegmon as to gaseous contents, and the bile for bacilli contained in it.

4. Experiments upon rabbits, which often give negative results with the Bac. Chauvoi.

Related Varieties (Pseudo-edema Bacilli).

Bacilli have been described by numerous writers which also kill experimental animals, with the production of bloody and emphysematous edema, but which do not correspond exactly with the bacilli of malignant edema or symptomatic anthrax. Recently v. Hibler has devoted a special study to these varieties and found representatives of most of the forms described which deviate somewhat in individual properties.

All these forms differ from malignant edema in the absence of thread-formation, growing as short rods, like symptomatic anthrax, and in pairs, and no more distinguishable from one another than some of the water vibriones. The following will give some idea:

Aside from the absence of thread-formation, the following correspond very well with malignant edema: the pseudo-edema bacillus of Liborius (Z. H. 1, 163) (according to Liborius, it has two spores in a single cell) and the Bacillus emphysematis maligni of Wicklein (Virchow's Archiv, cxxv, 75), while Kerry's new patho

genic anaerobic bacillus (Oest. Z. f. Veter., v, H. 2 and 3) differs in the rapid fermentation of milk and absence of a dark color in brain nutrient media. Klein's new bacillus of malignant edema (C. B. x, 186), and also Sanfelice's Bacillus pseudocdematis maligni (Ann. Inst. d'Igiene di Roma, 1, 375), do not liquefy gelatin nor coagulate milk, and darken brain nutrient media intensely. Compare also what is said under Bac. sporogenes Klein. These findings naturally make the diagnosis of symptomatic anthrax much more difficult.

Bacillus phlegmonis emphysematosæ. E. Fränkel.1 Synonym.-Bacillus capsulatus aërogenes Welch ?

Literature.-E. Fränkel (C. B. XII, 13; and monograph, Hamburg, 1893); P. Ernst (Virchow's Archiv, CXXXIII, 308); Welch and Nuttall (Johns Hopkins Hosp. Bulletin, July and Aug., 1892; Journal of Experimental Medicine, 1, 5, 45); Dunham (Johns Hopkins Hosp. Bul., April, 1897).

66

We are very much in doubt whether the producers of gas phlegmons," "foaming liver," "development of gas in the blood and internal organs," described under these names, are always the same organism, and in what way they are related to other anaerobes. At any rate, considering the variability of bacteria, their identity is possible. All the organisms appear to have the following properties in common: they are plump bacilli, which are occasionally arranged in long pseudothreads, which present no spontaneous motion, are stained well by Gram's method, and very rarely (best upon blood-serum) form spores, which are observed either at the pole or middle of the bacilli. Welch and Nuttall usually found a capsule, the German writers say nothing about it. Grape-sugar is very rapidly fermented.

In guinea-pigs emphysematous phlegmon is produced (E. Fränkel, Ernst), in which the tissues are often destroyed like tinder. The effect upon mice is variously given.

1 The name of Welch is a little older, but, in the first place, it is not formed upon the binomial plan, and, in the second place, it is liable to cause confusion, since Bacillus capsulatus has been used repeatedly and there is a bacillus (or bacterium) generally known as aerogenes.

Welch and Nuttall found, at least in their first cases, no pathogenic properties for animals, but observed marked formation of gas in an animal which was killed soon after the intravenous injection of 0.5 to 1 c.c. of the culture.

The organism has been rather infrequently isolated from men with abscesses containing gas, etc. Here also belongs the Bac. cadaveris butyricus Buday (C. B. XXIV, 369).

Occasionally there also occur gaseous phlegmons and similar diseases of internal organs, in which are found the Bact. coli alone or usually in combination with other varieties, but without any anaerobes being present. See Bunge (Fort. der Med., 1894, XII, 533).

Bacillus alvei. Chesire and Cheyne (Jour. Royal Microsc. Soc., 1885).

Synonyms: Bacillus of the foul-brood of bees (French, "Loque "'). Microscopically: Straight, fairly sturdy rods (0.8 μ thick and 2.5 to 5 μ long), sluggishly motile, large spores in spindle-shaped bulgings. The spores show polar germination. Our culture did not sporulate. Gelatin plate: Colonies first round, then they become provided with peculiar sturdy outgrowths, resembling wisps of straw or tendrils and very tortuous. Similar appearances occur in the stab culture. Gelatin is liquefied. In the stab there are often only single liquefying colonies, which are surrounded by radially arranged liquefying outgrowths; often the picture looks like an ink blot surrounded by fine outshoots. Upon potato a yellowish, upon agar a white, growth. Milk is first slowly coagulated; later the coagulum is dissolved and the reaction is faintly acid. The organism is only a facultative anaerobe; our culture from Král grows also aerobically. Aerobic potato cultures are delicate. It produces neither indol nor H2S, and no gas upon nutrient media containing sugar.

It is the cause of the characteristic disease of bees.

We are not familiar with the actively motile Bacillus piscidicus agilis N. Sieber, which was described as a facultative, anaerobic, short bacillus with spores and which exhibited marked pathogenic effect upon fish (C. B. XVII, 888). O. Wyss held it to be the Bact. vulgare, which it certainly approaches very closely. N. Sieber, in his reply to Wyss, makes no mention of spores. Z. H. XXVII, 143, and XXVIII, 159.

The Anaerobic Producers of Butyric Acid.

While medical men have studied the anaerobic varieties from the pathogenic standpoint, and only secondarily in