From the point of view of heredity, development and general vital characteristics Poincare was found to resemble most his mother and grandmother, who, with collateral relatives, are said to have shown special aptitude in mathematical calculation. Several male members of the family have had successful careers in neurology, law, meteorology, politics and mathematics. Poincare's development was not precocious, although he was bright and showed, when quite young, mathematical ability of an unusual order. His history, up the age of thirty years, at which time he was elected to the Academy of Sciences, was not unlike that of many other mathematicians whose freedom from the necessity of experiment allows them to make rapid progress. He was at one time troubled with rheumatism, and in his childhood suffered from an attack of diphtheria, followed by paralysis. This attack is said to have profoundly modified his nervous system, perhaps providing the neuropathic basis for traits shown later in life, such as awkwardness, restlessness, flighty attention, distractibility and general sensori-motor deficiency. A physical examination which dealt mainly with anthropometric measurements, strength tests, and with an inquiry into habits of eating, sleeping, and the use of narcotics, revealed nothing very unusual. Poincare had head measurements somewhat larger than the average. He was troubled with indigestion, also with insomnia. He did not use tobacco, and indulged only sparingly in wine and coffee. He was able to work for but four hours a day, in two-hour periods, and the tendency to automatisms and the perseverance of psychic activity compelled him to cease work for some time before retiring. He disliked muscular exercise except for the automatic processes involved in walking. His absent-mindedness was a matter of common comment among his associates. The examination of his sensory and motor capacity showed Poincare to have been rather feeble from a sensory point of view. Hearing was defective for low tones, but auditory orientation and localization were fair. He was shortsighted, but had no astigmatism; tests of the field of vision showed no abnormality. Muscular weakness of the eyes was present, which led to accommodation spasms. His general bodily movements were characterized by uncertainty, irregularity, awkwardness and hesitancy, and his muscular reflexes were prominent.