A note on the Treatment section. This is manifestly not the last word or even, we hope, our own last word, since the systematic work of the Massachusetts Commission must be kept up for some years to get a reliable verdict. Some of the results give rise to greater optimism than has prevailed in asylum circles, especially re general paresis. We are confident that _no one can now successfully make a differential diagnosis between the paretic and the diffuse non-paretic forms of neurosyphilis in many phases of either disease_, even with all laboratory refinements. If this be so, it is _improper not to give the full benefits of modern treatment to all cases in which the diagnosis remains doubtful_ between the paretic and the diffuse non-paretic forms of neurosyphilis. We ourselves advocate modern treatment, not only in the diffuse, but also in early paretic forms of neurosyphilis. It would have been out of place in a book in this Case History Series to have dealt extensively with the history of our topic. We have compensated inadequately for this lack by a few remarks at the head of the Summary and Key. We are, like all others in the field, under the inevitable obligation to Nonne of Hamburg, whose great work has gone into three editions, the second of which has appeared in English translation (Nonne’s Syphilis of the Nervous System, C. R. Ball, translator). Mott’s work, embodied in a large volume of the Power-Murphy System of Syphilis, has also been attentively consulted, as well as the various systematic works on neurology and psychiatry. The topic of Neurosyphilis is getting wide and appropriate attention in this country through special journals, both those dealing with nervous and mental diseases, and those dealing with syphilis. Syphilis is in a sense the making of psychiatry and will go far to pushing psychiatry into general practice. At the last moment we have been led to deviate from our plan of presenting only local cases familiar and accessible to us. In a section on Neurosyphilis and the War, we present excerpts and digests of English, French, and German cases of neurosyphilis that have appeared in association with the war. Our own country has not suffered greatly as yet either from the lighting up of neurosyphilis under martial stress or from the immediate or remote effects of syphilis obtained in the unholy congress of Mars and Venus. Space forbids a large collection of these martial cases, but, as will be seen, a fair sample of problems is presented. Speaking for the moment as the senior author of this book, I wish to say that, were it not for the energy, industry, and ingenuity of the junior author, Dr. H. C. Solomon, the book would not have been written. Nor, in all probability, would the systematic work of the Commonwealth on neurosyphilis and its treatment ever have been begun. I can also accord the highest praise to Mrs. Maida Herman Solomon for her social-service work in this new field.