Bacterium termo is regarded by leading authorities as the special ferment or causative agent of putrefaction[26] (Billroth, Cohn). [Footnote 26: Others have referred putrefaction to vibriones, less precisely described.] Bacillus includes, hypothetically at least, several species; as Bacillus subtilis, the innocent hay-fungus; Bacillus anthracis, the microbe of malignant pustule (anthrax, milzbrand, charbon) and the splenic fever of sheep; Bacillus typhosus (Klebs, Eberth, Meyer) of typhoid fever; Bacillus lepræ (Hansen, Neisser, Cornil, Koebner) of leprosy;[27] Bacillus malariæ, reported as having been demonstrated[28] by Klebs and Tommasi Crudeli, Marchand, Ceri, and Ziehl; Bacillus tuberculosis (Koch, Baumgarten, 1882); the bacillus of malignant oedema (Gaffky, Brieger, Ehrlich); that of syphilis (Aufrecht, Birch-Hirschfeld,[29] Morrison); of glanders (Loeffler, Schuetz, Israel, Bouchard); of pertussis (Burger); besides the Actinomycosis of Israel, Ponfick,[30] Bollinger, and others. Koch has very recently (1883) been reported to have discovered in Egypt the bacillus of cholera. [Footnote 27: Dr. H. D. Schmidt of New Orleans, an experienced pathologist, reported (_Chicago Medical Journal and Examiner_, April, 1882) that critical examination of numerous specimens of tissues from three cases of leprosy under his care failed to verify the existence of bacilli as characteristic of that disease.] [Footnote 28: Not certainly, however, as shown by Sternberg (_Bulletin of Nat. Board of Health_, Supplement No. 14, July 23, 1881). Dr. Salisbury of Ohio in 1866 made a series of observations, on the basis of which he asserted the discovery of a genus of malarial microphytes, which he referred to the family of _Palmellæ_. The oval and spherical organisms described by Richard and Laveran as found in the blood of malarial patients resembled micrococci rather than bacilli.] [Footnote 29: More recently described by him as micrococci.] [Footnote 30: _Die Actinomykose_, 1881.] [Illustration: FIG. 1. Micrococci: _a_, zoogloea form; _b_, micrococcus from urine, in rosary chain; _c_, rosary chain from spoiled solution of sugar of milk (Cohn).] [Illustration: FIG. 2. Bacteria: _a_, zoogloea of _Bacterium termo_; _b_, pellicle of bacteria from surface of beer; _c_, _Bacterium lineola_, free; _d_, zoogloea form of _B. lineola_.] [Illustration: FIG. 3. _Bacillus malariæ_ of Klebs and Tommasi Crudeli.] [Illustration: FIG. 4. Bacteria from gelatin solution, inoculated from swamp-mud, X 1500 (Sternberg).] [Illustration: FIG. 5. Vibrios in gelatin culture-fluid, X 1000 (Sternberg).] [Illustration: FIG. 6. Protococcus from slides exposed over swamp-mud, X 400 (Sternberg).] [Illustration: FIG. 7. Bacilli from swamp-mud, X 1000 (Sternberg).] [Illustration: FIG. 8. Bacilli from septicæmic rabbit, X 1000 (Sternberg).] [Illustration: FIG. 9. Bacilli from human saliva, X 1000 (Sternberg).] [Illustration: FIG. 10. _Bacillus anthracis_ (Sternberg).]