of this form appears to be as a variety of Act. chromogenes. According to Gasperini, this form may cause actinomycosis in cattle.

Actinomyces violaceus. (Rossi Doria.) Gasperini.

Found many times in Rome by Doria. It liquefies gelatin. The nutrient media are discolored. Gelatin becomes bright wine-red, agar grayish-violet, potato reddish-brown.

Streptothrix aurantiaca, citrea, albido-flava have been described by Rossi Doria (7. c.), and their standing as species must be proved by further comparison. According to Gasperini, they are all to be considered as actinomyces.

Lachner-Sandoval (l. c.) has studied in detail the Actinomyces albido-flavus Gasp. He describes the germination of the conidia as accompanied by elongation, many times following two directions simultaneously. The vegetative forms were killed by 70° in three minutes; the conidia by 80° in five minutes.

A "streptothrix" which is not acid-proof, and which possesses pathogenic properties for animals, was isolated by Rullmann from sputum (Münch. med. Wochenschr., 1898, 919). Upon Löffler's serum it furnished chrome-yellow growths, otherwise they were colorless. Often the cultures give off a moldy odor.

Actinomyces erysipeloidis. (L. and N.) Lachner

Sandoval.

Synonyms.-Oospora erysipeloidis L. and N., Streptothrix Rosenbachii Kruse.

As the cause of the rare sporadic disease, chronic erysipelas, erythema migrans, "erysipeloid" of Rosenbach, the latter author has described a true branching microorganism, related to the "cladothrix," but often occurring in the form of short rods and spheres. The threads often terminate in "a thick point. The description of the cultures reminds one most of mouse septicemia. In all growths they become brownish. It grows best at about 20°, less well at incubator temperature. When inoculated into man, it causes non-febrile, intensely itching, sharply outlined redness, which spreads slowly.

Actinomyces necrophorus.1 (Flügge.) L. and N. Bacillus of diphtheria in calves (Mitteil. des Kais. Ges. Amts., II). Bac. diphtheriæ vitulorum Flügge and B.

1 Since Flügge gave both the above names simultaneously, we are free to choose between them. The species designation of "necrophorus" seems to us to be especially happy.

necrophorus Flügge, Necrosis bacillus Bang (C. B. XIII, 201). Streptothrix cuniculi Schmorl. Actinomyces cuniculi Gasp. (Deut. Zeitschr. f. Tiermed., XVII). The organism lies in the necrotic tissue (diphtheritic membrane, etc.) on the side turned away from the surface as long, often radially arranged meshes or bundles, separated from healthy tissue by a narrow, necrotic zone. It is an obligate anaerobe, growing best on blood-serum or blood-serum agar at incubator temperature, and has been incompletely described as to its morphology (branching!). It is of great practical interest as the cause of numerous diseases in animals. It was cultivated by Schmorl from a destructive epidemic in rabbits, and first described by Löffler as the cause of calf diphtheria (mouth, larynx, nose). According to Bang, it also causes in young and old cattle, horses, and swine the most various necrotic affections (panaritium, gangrenous pock, intestinal diphtheria, liver abscess, vaginal and uterine diphtheria, etc.). We were unable to study this evidently important organism.

Regarding thermophilic varieties of actinomyces, see Kedzior (C. B. L. III, 154) and Tsiklinsky (C. B. xxv, 385).

After subcutaneous inoculation of mice, Löffler obtained the picture of progressive connective-tissue necrosis. A layer of lardaceous infiltration extends subcutaneously from the point of infection and envelops the kidneys, liver, and intestine with yellowish masses of exudate. According to Löffler, rabbits are not affected characteristically; but according to Schmorl and Bang, they are. All investigators found other experimental animals to be immune.

APPENDIX II.

Higher Fission-fungi. (Higher Fissionalgæ.)1

The close relationship with the chlorophyllaceous algæ is still more evident in the varieties of this section than in

1 We have had little personal experience with this group, and limit ourselves partially to a critical review of the literature.

all the forms previously discussed, and many investigators consider them as true algæ. On the other side, the connection with the simple fission-fungi is still so close that at least a brief mention seems necessary.

In distinction to the true bacteria, the members of this group have this in common, that the threads can be recognized as having a basal (not growing, often attached) and an apical (growing, free) end. 1 The ends are often of different thickness.

Key to the Recognition of Some of the More Important Genera of Fission-algæ.

Threads without distinct sheaths:

(a) Without sulphur granules. Leptothrix Kützing, see below. (b) With sulphur granules, motile, not attached. Beggiatoa Trevisan, page 461.

Threads with sheaths:

(a) Without sulphur granules.

1. Without pseudodichotomous branching. Crenothrix Cohn, page 463.

2. With pseudodichotomous branching. Cladothrix Cohn, page 465.

(b) With sulphur granules. Thiothrix Winogradsky.

Leptothrix epidermidis Biz.2

(Plate 69.)

Microscopic Appearance.-In our preparations there are sturdy unbranched threads, distinctly jointed and readily falling apart, with no evident distinction as to base and apex. Young cultures show bacilli about like the B. mesentericus (69, X1 and XII).

Motility. The young rods present distinct motion like that of bacilli. We were unable to stain flagella.

Staining Properties.-Stains with all anilin dyes and by Gram's method. With iodin and iodid of potassium alone there is no blue stain.

1 We must certainly admit that the discernment of the two ends has often caused greater trouble than was to be expected from the statements of Bücher, for example, in the case of Beggiatoa.

2 Before the leptothrix of the mouth had been cultivated we could place the L. epidermidis among the "true" leptothrices only with reservation. (See p. 461.)

Relation to Oxygen.-Grows better with the admission of oxygen.

Requirements as to Temperature and Nutrient Media. Grows luxuriantly and rapidly at room and incubator temperature upon all nutrient media.

Gelatin Plate.-(a) Natural size: At first, minute white points which liquefy the gelatin as soon as they become a little larger-after twenty-four to forty-eight hours. The older colonies exhibit a small white flake in the center of the liquefied areas; also the edges of the areas present a whitish border (69, VIII).

(b) Magnified fifty times: Young, superficial colonies present a pretty convolution of curly, wavy threads. The center soon becomes dark and cloudy and sinks in, while there remains a row of fine radiating hairs as a peripheral

zone. As the liquefaction advances there is finally a flat, gray saucer, which presents a delicate hairy border toward the solid gelatin, and in the center of which is a curly mass whose structure becomes more and more indistinctly crumbly (69, IX).

Gelatin Stab.-After twenty-four hours there is formed a conical area of liquefaction with whitish flocculi, and at the apex crumbly, yellowish-white masses of bacteria. gradually accumulate. After four or five days there forms a grayish, tough pellicle on the surface (69, 1).

Agar Plate. (a) Natural size. Superficial colonies: White or yellowish white, sharply outlined growths with smooth but irregularly notched borders. The deep colonies remain small, dense, yellowish-white (69, v).

(b) Magnified fifty times. Superficial colonies: The center is opaque, brownish-yellow, passing gradually into a yellowish-gray peripheral zone which consists of very closely set, fine, radiating hairs (69, VI). Deep colonies: Roundish, nodular, yellowish-brown, here and there presenting single or bunched projecting hairs (69, VII).

Agar Stab.-Surface growth: Yellowish-gray to brown, rather smooth-bordered, slimy. Gradually it becomes dull, with some whitish elevations. In the stab the growth is like a grayish-white thread. After several months the agar becomes colored dark brown (69, III and IV).

Agar Streak.-Like the surface growth of the stab culture. Upon the water of condensation is a tough, wrinkled, brownish pellicle. Where this passes on to the tube-wall it is pure white. The water of condensation is clear (69, II).

Bouillon Culture.-Only on the surface there is a tough, thick, wrinkled pellicle, which is firmly adherent to the glass.

Milk Culture.-On the surface a dense scum. The milk is not coagulated, and while the milk becomes transparent, a limited white precipitate is formed.

Potato Culture.-There is rapidly formed an elevated, reddish to grayish-brown, sharply outlined growth. In time the surface develops wavy wrinkles. In old cultures the peripheral zone presents a white, chalky discoloration (69, x).

Spores.-There are no endospores.

Distribution.-Found by Bizozzero upon the skin of healthy men.

Related Varieties.-This variety resembles in many points the subtilis-mesentericus group. Wavy growth, vigorous liquefaction, and air hyphæ upon potato are observed, in which respects its cultures are very similar to those of the B. subtilis. The variety is more properly called Bacillus epidermidis. To be sure, it must then be taken for granted that accidentally a spore-free form of bacillus is exemplified in this variety.