The entrance of the microbe by wounds must always be counted on, and explains the casual inoculations, by bites of dogs, insects, worms, by barbed wire fences, by wounds with horns, tusks, or feet, by nails, etc., and in winter by hard, woody aliment scratching the lips, mouth, fauces or pharynx. Shedding of teeth, diseased teeth or gums, and everything that causes abrasion of the alimentary mucosa must be admitted into the list of causes. Infected traumatisms of any kind, like intratracheal and intravenous inoculations usually prove fatal, while infection by ingestion is not necessarily so. The pathogenic potency appears to be impaired in the stomach or intestines. _Symptoms._ These vary widely according to the subject, the seat of infection and the violence of the attack. They may be classed under three principal heads: _superficial_, _thoracic_ and _intestinal_, and in addition into _acute_ and _chronic_ cases. In the _superficial_, _external_ or _cutaneous form_ there is usually a sudden onset with high fever (104° to 107° F.), accelerated pulse, (70 to 90), and breathing (24 to 50), anorexia, suspended rumination, muscular tremors or shivering, staring coat, dry, hot muzzle, burning of ears, horns and hoofs, suppression of milk, and more or less stringy salivation. The visible mucosæ are of a deep red or violet tinge, and the patient will often remain apart by himself when the herd has moved elsewhere. Soon there develops a tense, hard, hot, painful swelling of the intermaxillary space, tongue, throat, neck, dewlap or elsewhere, amounting to perhaps six inches in thickness, extremely resistant and not usually indented on pressure with the finger. The breathing becomes stertorous and deglutition difficult or impossible. The mouth is hot and filled with tenacious saliva, and the tongue may hang pendant while on its borders and lower surface are projections of the mucosa swollen by infiltration, yellowish and semi-transparent, or blood-stained. At other points petechiæ are more or less abundant. Death may take place from pharyngeal obstruction or closure, or as the disease advances, there may be indications of implication of the viscera, of the chest or abdomen: encreasingly difficult breathing, a mucous or suffocative cough, colicy pains, tenesmus, and the passage of moulded glazed fæces, of pseudo-membranous casts, or of profuse liquid stools. The animal may move the hind feet uneasily, lie down and rise alternately, may remain persistently recumbent until death, or he may stand up until he falls to perish of asphyxia. Death may occur in six hours, or may be delayed four days.