In addition to the skin the nerves are also affected, not always at the commencement, but always in the later stages. Whether all peripheral nerves are affected we cannot say--certainly the facial, radial, ulnar, median and peroneal are always diseased. According to our investigation the nerves of the extremities are affected throughout their whole length, but the affection is severe only at certain places, viz., where the nerves run superficially over bones or joints, as the median at the wrist, the ulnar at the elbow, and the peroneal where it crosses the fibula. As a result of this nerve affection we have pain followed by anæsthesia. The pains in the arms, hands, feet and calves are sometimes very severe and persistent. The affection at first causes pain, by pressure on the nerves, and later--when the pressure has led to atrophy--anæsthesia. Now since, as we shall later clearly demonstrate, leprous affections tend to heal, it is not infrequently the case that nerve affections, when slight, pass off without having specially injured the nerves, and these nerves may be the seat of fresh infections, and thus the patient suffers from repeated painful attacks through a course of years. This is particularly the case where there is general infiltration of the legs, and is either the result of repeated attacks of the same, or of the implication of different nerve branches. The nodules are often painful when first developed, but later on sensation is deadened. Of internal organs, the testicle, liver, and spleen, are always affected in this form, but we shall consider them later in the description of the pathological anatomy. Before we more closely describe the course of the disease, we shall first briefly discuss the fate of the nodules. These usually remain for years unchanged, growing very little or not at all. The skin over and around them, or rather its vascular supply, is very sensitive to changes of temperature, so that the skin, as we have already indicated, changes its colour with change of temperature from dilatation of the blood vessels. The vessels evidently suffer from the invasion of the leprous poison. New outbreaks have often the appearance of an “erythema nodosum,” with great hyperæmia. We had once the opportunity of examining a piece cut out of such an erythema-like eruption, and found dilated vessels and round cells, and only after long search a few bacilli. One must conjecture that there is deposited with the bacilli a chemical poison which affects the vessels, or that the bacilli produce the poison, and that this poison has its action only in its immediate neighbourhood.