From the clinical histories of the seventeen cases here reported and from a review of the literature along these lines, we can at least arrive at the following tentative conclusions concerning the associated mental disturbances of alcoholic neuritis.I. The neuritic disturbances may take several distinct varieties, either as a central or peripheral eye-muscle palsy, in the sense of a neuritis of the peripheral fibres of the various ocular nerves, or changes in one of the numerous cell groups of origin of the oculo-motor nerve in the region of the central grey matter. In one case this may give rise to either a ptosis or an isolated paralysis of one of the eye muscles, when of peripheral origin, or when there is a central change a complete ophthalmoplegia may result. In the latter case we have the complex of an acute polioencephalitis and we have already seen the close relation of this complex to delirium tremens and Korsakow's disease.The associated mental disturbance, whether the eye-muscle paralysis be of central or peripheral origin, is caused by the profound implication of the higher central neurones, and we have either a delirium with marked allopsychic disorientation or a fabricating psychosis. On the contrary there may be a peripheral neuritis in the ordinary acceptance of the term, with the associated central changes in the form of a degenerative process in the posterior columns of the cord and their nuclei in the nedulla. This posterior column degeneration has been so marked at times, combined with the neuritic pains, that it bears a strong resembalance to tabes, so strong, in fact, that Dejerine has proposed the name of neuro-tabes for this symptom. Signs of a peripheral neuritis, may, however, be entirely absent, the lesion being preeminently of central distribution, with a parenchymatous degeneration of various systems and their cells, and manifested clinically only as a terminal disorder with peculiar and prominent, but almost pathognomonic motor symptoms. Sometimes there exists a combination of a peripheral with a central change, either in the sense of a true peripheral with a central neuritis or a peripheral eye muscle paralysis combined with a delirious state. There are, however, no sharply limited types, as cases of ordinary peripheral neuritis are nearly always associated with central lesions. This has been especially well shown by the recent work of Cole, who also looks upon the mental disorders of alcoholic neuritis as closely related to the central changes, both in the sense of the axonal reaction of the Betz cells with a degeneration of their connected fibres in the pyramidal tracts and of a well marked posterior column degeneration analogous to tabes.2. There may exist the form of psychosis described by Korsakow, but which also may occur without any signs of a peripheral neuritis and in addition may be caused by other factors besides alcohol. It may arise out of a depressive or stuporous state, an acute hallucinosis or an ordinary delirium tremens, the latter, especially if associated with transitory neuritic disturbances, may present many allied features of the height of the disease.3. A delirious state, strongly resembling delirium tremens, but of a very acute onset and when associated with signs of a peripheral neuritis, there may exist in addition a marked disorientation, extremely poor retention, defective memory for recent events and confabulation. Under these conditions we have an acute Korsakow's disease. The confusion is usually deeper than in ordinary delirium tremens, especially if associated with an eyemuscle paralysis; the physical decay is extremely rapid and may end with the motor disorders of a terminal central neuritis. The course of the disease is usually acute on account of the rapidity of the pathological process.4. A very acute delirium of Korsakow’s type, with isolated neuritic symptoms and progressing rapidly to recovery.5. A true delirium tremens which may shade into a fabricating psychosis. In these cases, recovery is not complete, but there remains a light degree of mental deterioration, or the delirium may rapidly subside and leave a slowly improving neuritis. If neuritic symptoms appear during the delirium, there is always superimposed suggestibility and marked fabrications.It is these types which show the extremely close relation between delirium tremens and Korsakow's disease. These cases differ from our third group by the absence of physical deterioration and the strong tendency to a partial recovery.6. A group of cases with a protracted course, showing a marked depressive affect, with suicidal tendencies, strong religious ideas, episodes of great fear and anxiety and a marked hallucinosis. At the onset or height of the disease signs of peripheral neuritis are absent, but during the protracted course there develops emaciation with diarrhea, and finally rigidity and twitchings, all the clinical symptoms of a central neuritis. These cases, therefore, present a central neuritis as the particular neuritic lesion of the disease and they are closely allied to Meyer's delirious and depressive disorders.7. There may be a pure acute hallucinosis, entirely free from an allopsychic disorientation, in which the neuritic pains may form the basis of various delusional interpretations, analogous to the paræsthesias of the alcoholic paranoic states without neuritic signs. On the other hand, a peripheral neuritis may be absent during the hallucinosis to appear later in connection with typical fabrications and disorientation. Under both conditions the outlook for recovery is very favorable.8. Depressive delirious states of a very rapid course, with marked physical symptoms of a polyneuritis, or there may exist a dreamy hallucinatory confusion, but without fabrications or amnesia in either case.9. A fabricating delirium of an acute type, not resembling delirium tremens and showing striking features of difference from Korsakow's disease.1o. A group of cases resembling at first an alcoholic deterioration, with a marked recent memory defect, running a rather slow course, but with an almost complete recovery parallel with the improvement in the physical signs.