This form of leprosy was first distinctly and well described by Danielssen, who called it _L. anæsthetica_; but since the macules, as Danielssen recognised, play an important and constant _rôle_ in the course of the disease, we prefer the name maculo-anæsthetica, as it includes the two most striking symptoms; the name _L. nervorum_ used by many investigators, we do not consider satisfactory. Certainly the nerves suffer most, and the neuritis is the most prominent feature in the disease, but the skin affection is a bacillary one, which precedes or accompanies the neuritis; it is _not_, as is often believed, a tropho-neurosis, as we have determined by the demonstration of bacilli in both young and very old leprous patches. Thus there disappears the sharp distinction between the two forms of the disease--the tuberous and the maculo-anæsthetic. We must regard them as the same disease, only with varied intensity in the action of the bacilli. One can distinguish in the maculo-anæsthetic form, different stages in the course of the disease, but in general they cannot be very sharply defined from one another. In the prodromal stage, which is of very varied duration, lasting for months or even years, the patients state that they suffer from exhaustion, general debility, rheumatoid pains of the joints or muscles, hyperæsthesia of the skin, neuralgic pain of certain nerve regions, sopor and mental depression. Ephemeral eruptions of spots are admitted; and pigmentary anomalies, sometimes atrophic, sometimes hypertrophic, were noted by Bidenkap. Danielssen states that he has seen, at the very beginning of the disease, a slight vaso-motor disturbance, which is indicated by a bluish-red reticular appearance, which is evident most clearly on changes of temperature. These vaso-motor disturbances, which appear as slight patches which can be induced by friction, are chiefly characteristic of the maculo-anæsthetic, though they may appear during the earliest stage of the tuberous, form. In fact, our view is that the so-called prodromal symptoms are nothing more than the earliest, indefinite, undiagnosable phenomena of infection. One or more eruptions of pemphigoid bullæ may occur in the commencing stage, but we have more often seen them later, both accompanying the patches and in the stage of anæsthesia and mutilation.