The =febrile reaction= which is at first moderate, gradually increases in force; the animals become dull, drowsy, careless of food, and the hyperæsthesia merges into paresis or paralysis. This is rarely so complete as in fracture of the vertebræ. If the inflammation is restricted to the lower columns only, there may be akinesis without change of the sensitiveness or with hypersensitiveness. If restricted to the upper columns there may be sensory paralysis only on the opposite side. The =heart sounds and pulse= are usually altered, palpitations may appear early with acceleration and sharpness of the pulse, and this may alternate with a tardy slow pulse with intermissions. =Breathing= also becomes accelerated and in violent cases with trembling, though in moderate inflammation with effusion, softening and degeneration, it is liable like the heart beats to become slow and tardy. When =vertigo= appears it may be attributed to extension to the bulb or cerebellum, or to the sympathetic implication of these organs. The frequency with which paraplegia occurs in the large herbivora suggests a special susceptibility of the lumbar portion of the cord, probably in connection with severe muscular effort of the hind limbs. In protracted cases the fever may run very high, being complicated by septic poisoning from the numerous cutaneous sloughs and sores, as well as by cystitis and nephritis. _Diagnosis._ This may be based on the progressive onset, unlike the sudden attack of congestion; on the occurrence of primary fever with hyperæsthesia or even muscular rigidity, merging into a later paresis or paralysis; on the retention of urine, followed by incontinence; on the torpor of the rectum; on the extreme tenderness of the spine in the region of the inflammatory lesion; and on the tendency to rapid atrophy of the affected muscles, and the death and sloughing of the skin under pressure over the prominent parts of the body. The definite localization of the muscular symptoms, and the different temperature and secretion of the affected part of the skin, from the unaffected, are further confirmatory of myelitis.