3. Would not a circular course or recurrence of attacks be decisive for manic-depressive psychosis? Paretic neurosyphilis sometimes exhibits the same circular or recurrent course. We conclude that neither the clinical symptoms, the classical pupillary and speech signs, nor the ups and downs of a particular disease, are at all decisive as between manic-depressive psychosis and paretic neurosyphilis. Resort must be had to laboratory tests. 4. What is the significance of the high blood pressure in paretic neurosyphilis? Work from our laboratory (Southard and Canavan) has shown plasma cells in the kidneys in 17 out of 30 paretics (56%), and in 16 of these 17 paretics with renal plasmocytosis, the plasma cells were found in the periglomerular region. What the relation of these findings may be to heightened blood pressure is as yet unknown. The severe syphilitic involvement of the aorta so characteristic in paretic neurosyphilis, as in other forms, may possibly have a bearing on blood pressure. =A POSITIVE SERUM WASSERMANN REACTION associated with mental symptoms (even with grandiosity) does NOT prove the EXISTENCE OF PARETIC NEUROSYPHILIS (“general paresis”).= =Case 11.= Juliette Lachine came to a general hospital with pain in the right upper quadrant of the abdomen, wherein was found an enlarged liver. This liver was regarded as syphilitic on the ground that the patient had a positive serum W. R. and that her two elder children were clearly suffering from congenital syphilis. The liver mass was promptly reduced by antisyphilitic treatment of the classical sort. When, however, the patient was given an injection of salvarsan, she shortly began to develop marked mental symptoms, whereupon she was removed to the Psychopathic Hospital. The =mental picture= at the Psychopathic Hospital was as follows: Lack of orientation for time, marked distractibility of attention, with a certain jumping from one subject to another, delusions of a religious nature, claims of wonderful powers possessed by the patient, moods variable, though as a rule of a euphoric and elated nature, with laughing and singing. The activity seemed to be of a mental rather than a peripheral nature. The patient did not regard herself as mentally abnormal. The liver was still 4 cm. below the costal margin in the nipple line. We found the W. R. to be positive in the serum but negative in the spinal fluid. In fact, the spinal fluid was entirely negative. So far as we are aware the picture presented by this case is one of MANIC-DEPRESSIVE PSYCHOSIS. We regard the disease as merely complicating the syphilis, although it is entirely possible that some visceral condition incidental to the syphilis might be proved (in a higher stage of psychiatric science) to have produced the mania.