isolated attack of mania in that period of life. He differentiates this condition from agitated melancholia, leaving the question open as to whether this constitutes a pernicious form or is a presenile disease. According to Bumke, psychic causes are more prominent in involution melancholia than in the manic-depressive psychoses, the duration is longer and they do not make such complete recoveries, the most common termination being a depressive mental enfeeblement, with despondency and an anxious hypochondriacal mood. For the genetic interpretation of climacteric melancholia as well as the other involutional forms the intimate association, according to Bumke, of endogenous with exogenous factors is the point of greatest importance. "Involution only brings the barrel to an overflow; it only adds exogenous to the individual endogenous momentum so that the sum total leads to the outbreak of a manifest psychosis." Seelert goes still further with the endogenous exogenous theory of Bumke. "It depends on the type of the association whether the organic anxiety psychosis, a melancholia or the depression of a manic-depressive insanity develops in the later period of life. In one the endogenous factors predominate, in the other the exogenous and in melancholia (in its narrower sense) the two maintain a balance." Although, as has been noted, no characteristic pathological changes have been associated with involutional melancholia, a condition to which attention was called by Adolf Meyer should be referred to here. In 1901, in an article in "Brain" on "The Parenchymatous Systemic Degenerations mainly in the Central Nervous System" he proposed the name "Central Neuritis" for a terminal affection previously described by Turner in 1899 and occurring more frequently perhaps in involutional melancholia than in any other psychosis:—"This alteration has been found to occur in peculiar forms of end stages of depressive disorders, near or after the climacteric period, alcoholic-senile and alcoholico-phthisical cachectic states, idiocy, and perhaps also general paralysis (Turner's case). Ordinary infectious and cachectic states do not, however, appear to form an important link in the causes."[292] The mental condition is usually anxious, agitated and apprehensive, often terminating in a delirium followed by a stupor. The disease may last for a few days ending in death or may recover after several weeks. It is accompanied by progressive weakness, loss of weight and wasting, a slight rise of temperature, and in many cases attacks of diarrhea. Characteristic are muscular tension with rigidity, twitching movements, incoordination and jactitation of the limbs. The reflexes are usually increased. The onset is often quite sudden, usually in the fourth, fifth or sixth decade of life. At autopsy a striking condition, described as axonal alteration, is found in the "Betz" and other large ganglion cells generally. The cell body