subject, taken in conjunction with physiological experiments, and with only the aid of a very few isolated facts of positive morbid anatomy. I need hardly say that I am none the less anxious for that further assurance which we shall one day, perhaps, obtain by means of greatly-improved processes for microscopic detection of minute changes in nerve-centres; but, looking to the necessary rarity of opportunities for post-mortem examinations of the nervous system in any but the most advanced stages of neuralgias, it will hardly be disputed that, if I am right in my main position, we are singularly fortunate to be so unusually independent of the need for this source of information. 1. The first fact which strikes me as of decided importance is the position of neuralgia as an hereditary neurosis; and this character of the disease is so pregnant with significance, that I shall take some considerable pains to put the fact beyond doubt in the reader's mind. There are two series of facts which support the theory of the inheritance of the neuralgic tendency: (_a_) instances in which the parent of the sufferer had also been affected with the disease; and (_b_) instances in which the family history of the patient being traced out more at large it appeared that, among the members of two or more generations, while one, two, or more individuals had been actually neuralgic, other members had suffered from other serious neuroses (such as insanity, epilepsy, paralysis, chorea, and the tendency to uncontrollable alcoholic excesses), and, in many instances, that this neurotic disposition was complicated with a tendency to phthisis. (_a_) The question of the direct transmission of neuralgia itself from the parent seems the easiest of decision, though even this cannot always be satisfactorily cleared up by the hospital patients, among whom one collects the largest part of one's clinical materials. However, I have been at the pains of investigating a hundred cases of all kinds of neuralgia, seen in hospital and private practice, with the following results: twenty-four gave distinct evidence that one or other parent had suffered from some variety of neuralgia; fifty-eight gave a distinctly negative answer; and eighteen would not undertake to give any answer at all. Among the twenty-four affirmatives are inserted none in which the history of the parent's affection did not clearly specify the liability to localized pain, of intermitting type, but recurring always in the same situation during the same illness. In three of these twenty-four instances, the patient stated that both parents had suffered from such attacks, and, in one of these, it appeared that the grandfather had likewise suffered.