CHAPTER III. BACILLUS COLI COMMUNIS. THE Bacillus coli was first isolated from human feces in 1885 by Kmmerich, who thought that it was the spe- cific cause of Asiatic cholera. Many investigators have since studied its peculiarities, until at the present time it is one of the best-known bacteria. It is habitually present in the fecal matter of most ani- mals except the horse, and in water and soil contaminated FIG. 109.—Bacillus coli communis, from an agar-agar culture; x 1000 (Itzerott and Niemann). with it. With water or dust it gains entrance into the mouth, where it can frequently be found, and occurs accidentally in foods and drinks. During life the organ- ism sometimes enters wounds externally from the surface of the body or internally from the intestine, and is a cause of suppuration—or at least occurs in the pus. The Bacillus pyogenes foetidus of Passet is almost certainly identical with it. * 389