Thus, for example, among 49 cases of puerperal psychoses, _Hansen_ found that in 42 instances there was puerperal infection; and among 200 cases of puerperal eclampsia, _Olshausen_ found 11 patients suffering from mental disorder. The principal forms of insanity occurring at the puerperium are mania and melancholia, next in frequency come monomania (Ger. _Verrücktheit_), dementia (Ger. _Blödsinn_), alternating or circular insanity (_folie circulaire_), hallucinatory paranoia (chronic delusional insanity with hallucinations), and hysterical mental disorder. According to _Windscheid_, the commonest cases are those which are purely puerperal, the rarest those in which the insanity of pregnancy continues during the puerperal state; the age at which puerperal psychoses most commonly occur varies between 31 and 35 years, the average age being 29.1; multiparæ are more often affected than primiparæ; the outbreak of mental disorder most commonly occurs within a week after the birth of the child; there is nothing specific about the various forms of puerperal insanity, which are identical with the respective varieties owning another etiology. According to this author, before an attack of puerperal mania, prodromal symptoms usually occur, such as headache, dizziness (Ger. _Augenflimmern_), feelings of anxiety, insomnia, followed by various congestive symptoms, and either by great restlessness or by great apathy, and very often by indifference to the infant; to these symptoms succeeds the period of motor excitability, characterized by great bodily restlessness and by continued talkativeness; the culmination takes the form of a maniacal outburst, in which infanticide even may occur; the delirium runs mostly in erotic and religious channels. Puerperal melancholia also exhibits the usual clinical picture of this form of mental disorder; after prodromal headache, stupor sets in, often associated with attacks of anxiety and with hallucinations of sense, and always characterized by great loss of appetite and by a suicidal tendency.