The _Symptoms_ may be deferred for a length of time on account of the accommodation of the myelon to the slowly increasing pressure. When they do become manifest, it is usually at first by insensible gradations so that for a time their existence is questionable. Yet a case will sometimes reach a sudden climax, by reason of a blood extravasation or inflammatory exudate, and the signs of sudden pressure or acute myelitis or meningitis supervene. In the absence of sudden access of trouble, the symptoms are those of a slow increase of _motor troubles_ (local paresis, paralysis, paraplegia), or _sensory_ (hyperæsthesia, anæsthesia). Spasms may occur early or even later in the disease. From disorders due to cerebral lesions the morbid phenomena are distinguished by being paraplegic rather than hemiplegic; sensori-motor rather than sensory or motor; local rather than general; with intelligence and special senses clear, rather than dull or abolished; associated with marked muscular atrophy in the affected parts; advancing from behind forward rather than uniform throughout the body. The area of nervous disorder points more or less clearly to the seat of the lesion. Early implication of the fore limbs, and then later of the hind, suggests lesion of the cervical region. Dyspnœa tumultuous heart action, or vertigo may coincide. Tardy movements of the hind limbs, imperfect balancing, dragging, swaying, knuckling, involuntary flexions of stifle or hock, flexor contractions, standing on toe, cramps, paraplegia, indicate lesion in the dorsal or lumbar region. There may be palsy of the rectum, anus, bladder, sphincter vesicæ, penis, and vulva. Paralysis or other nervous disorder of the tail and sphincters ani and vesicæ, without implication of the hind limbs or quarters, may bespeak lesion in the terminal end of the spinal cord. With paralysis of the bladder the penis may be pendent out of the sheath, or being retained within it, the urine may dribble constantly into and from that cavity, and the vulva may be soft and flaccid. When the anus is involved, the adjacent part of the rectum usually participates becoming overloaded, the sphincter is soft and lax and allows a constant oozing, and the exposure of the mucosa. The paralytic tail hangs between the thighs, limp and flaccid, and becomes saturated with manure and in females with urine. Even in the earlier stages the symptoms are usually greatly aggravated by compulsory movements like turning in a circle, walking up hill, or (in dogs) up a stair, the arched back, the pendent head, and hesitating planting of the foot suggests walking on pins. For a more exact localization of the lesion the reader may consult the table indicating the functions of the different parts of the spinal cord. The early fatigue under exercise grows as in other progressive spinal lesions.