_Symptoms._ These vary greatly in different cases according to the part involved, the meninges or some special region of the cord, to the essential cause of the inflammation and its acuteness. Usually the attack sets in slowly in contradistinction to the abrupt attack of congestion. =Hyperthermia= and =rigor= are usually among the first symptoms, though in many cases =hyperæsthesia= is the most marked early symptom. The skin covering the muscles which derive innervation from the affected section of the cord is the most sensitive. This is often so extreme along the vertebral column that percussion on the spinous processes or pinching between the fingers and thumb causes the most pronounced wincing and dropping of the back. Copland and Laposso have noticed that a sponge of hot water drawn along the line of the vertebræ causes acute pain and contractions of the muscles of the back and limbs, which are almost tetanic in their force. This probably implies the existence of meningitis, since the absence of rigidity of the muscles of the neck, back and limbs, usually implies the absence of meningeal inflammation. It may, however, occur in localized or commencing myelitis. The existence of unilateral lesions and rigidity determines intense lameness, which is further characterized by the most marked hyperæsthesia. The =morbid phenomena of the motor system= are more characteristically paretic or paralytic than spasmodic. When rigidity or spasm ushers in the attack it is superseded in a few hours or in two or three days by flaccidity of the muscles of the affected part, with imperfect control or even complete paralysis. The muscles affected will depend on the seat of the spinal lesion. If in the neck it may affect fore and hind limbs, and even the chest and abdomen; if in the back or loins it will induce paraplegia, the anterior limit of which will correspond to the seat of the lesion; if near the caudal extremity of the cord, (lumbar portion), paralysis of the tail and of the sphincters ani and vesicæ may be prominent features. Retention of urine and fæces (spasm) may precede incontinence (palsy). =Common sensation= may be dull or abolished on one or on both sides. If on one side only, the other may show hyperæsthesia. =Trophic modifications= are very marked though they may not be noticeable at first. The paralytic muscles waste rapidly and the impaired nutrition is manifested in the rapid formation of sloughing and intractable sores where pressure comes in recumbency (the hips, stifles, hocks, shoulders, etc.). This is especially noticeable on parts supplied by the cord at or behind the seat of the lesions. =Vaso-motor changes= are usually marked by a preliminary hyperthermia of the affected parts, followed by a corresponding hypothermia. Sometimes the affected part of the skin will remain quite dry while the rest of the body is covered by perspiration. =Choked optic disc= and retinitis are sometimes present.