The knee-jerk is changed in somewhat more than half the cases, a little oftener exaggerated than abolished; but sometimes the reflexes are enormously increased all over the body, so that a strong puff of air in the face even will set the arms and legs going like a jumping-jack. I have twice seen the patellar reflex abolished in one leg, and so marked in the other as to seem to me exaggerated.[24] I have also known it to disappear {196} absolutely in both legs two weeks after it had been found to be excessively exaggerated. It also varies under conditions of rest, fatigue, excitement, etc. Intense pain in the joints occurs, and I have found it where the knee-jerk was exaggerated, in one case giving rise in a physician to the delusion that his arms and elbows had been resected. This may disappear in time. Charcot's joint disease has been observed. [Footnote 24: There was no evidence, and there had been no history, of a hemiplegic attack in either case.] In the final stages the bones are fragile and easily break; hemorrhages under the periosteum or perichondrium arise from trifling force or injury, giving rise to hæmatomata, the most common of which are on parts exposed to pressure, etc., as the ear. The patient is confined to his bed, fed like a small child, demented, hardly able to articulate the extravagant delusions which form such a grotesque contrast to his actual state, until the mind is as incapable of forming or receiving ideas as of expressing thoughts; and the body is simply a filthy, helpless mass of humanity, dying of exhaustion or decay, unless lung gangrene, bed-sores superficial and deep, necrobiosis, exhausting diarrhœa, pneumonia, pulmonary consumption, perhaps asphyxia from an epileptic fit or choking, have followed incontinence of urine and feces to the fatal end, or heart failure or apoplexy have closed the scene. PATHOLOGY AND MORBID ANATOMY.[25]—General paralysis of the insane is, according to Mendel, following Rokitansky's idea, a connective-tissue disease, affecting the nerve-cells and tissues secondarily, while Tuczek and Wernicke think that the primary disease is of the nerve-elements (primäre Atrophie der Nervenelemente)—a diffuse interstitial cortical encephalitis on the one hand, or a diffuse parenchymatous cortical encephalitis on the other. There is also, in well-marked cases, atrophy of the white substance, due, according to general opinion of pathologists, to primary interstitial encephalitis ending in sclerosis.