psychical conditions which depend on organic causes, and are therefore very analogous to psychical disorders; 13. because chronic delirium (mania) can be no other than febrile." Absurd as such discussions may seem at this time, they are no worse than the theological debates of that day. As a matter of fact, they were no more futile than the efforts still being made to classify the various psychoses on some one common ground, for any other than purely statistical purposes. Kraepelin[265] divides the psychoses due to infection into febrile delirium, infection delirium, acute confusional states (amentia) and exhaustions. The result of the infectious process, as he says, may be merely to precipitate a manic-depressive psychosis, or an attack of dementia praecox, general paresis or delirium tremens. It may also be manifested in the form of a neuritis, myelitis, encephalitis, or a meningitis. Bonhöffer in 1910 described several forms of "symptomatic psychoses" due to infections and divided them into three main groups: deliria, confusions and mental enfeeblements. He also referred to epileptiform excitements, dream states, hallucinoses, manic types and amentias either hallucinatory, catatonic or incoherent in character. Kraepelin speaks of several definite stages or forms of febrile delirium. In the mildest of these there is a feeling of discomfort with a sensation of fulness in the head and a marked sensitiveness to external impressions. In the second stage a suggestion of clouding becomes apparent and perception is distorted by hallucinations and illusions. There is an increased activity of the mental processes and consciousness soon assumes a dreamlike form. Hallucinations and illusions are mixed with realities. The restlessness increases and excitements or depressive moods may precede the appearance of the third stage. In this there is a more pronounced disturbance of consciousness with disorientation, confusion, flight of ideas, and variable emotional reactions, sometimes with actual manic manifestations. Evidences of stuporous tendencies may appear at times. In the fourth stage a state of weakness develops, with picking at the bed clothes, tremulous movements and a senseless muttering of words and syllables. This terminates in complete coma. In smallpox, scarlet fever, erysipelas, articular rheumatism and pneumonia there are often sudden confused excited states, while in typhoid fever stuporous delirium is the rule. Hendriks found the mental symptoms in typhoid greater during convalescence and not closely related to the febrile reaction. He describes a marked disturbance of attention with little involvement of apprehension or comprehension, but marked loss of mental capacity and sometimes a tendency to confabulation. Visual hallucinations and loss of sleep are common symptoms. Often there is restlessness, talkativeness, indifference, carelessness and disturbances of volition. In articular rheumatism and scarlet fever, according to