One meets also in old nodules, among apparently only unproductive elements, blood vessels surrounded by young cells (_Plate VI, Fig. 5_). This appears definitely to favour the view that the tumour cells are, at least for the most part, migrated blood corpuscles. These results have been obtained by examination of fresh nodules, and of those hardened in Müller’s fluid. As we have recently, while hardening the nodules in Fleming’s chromic and osmic acid mixture, and staining the sections with hæmatoxylin, been unable as yet to find any mitoses, and further, have found, by bacillary staining of an old section from a corneal node, an appearance like _Plate VI, Fig. 7_, we must maintain provisionally that in the lepromata the new formations are, at least chiefly, formed by the immigration of white blood corpuscles. As the round cells infiltrate the connective tissue, the fibres are pressed asunder, and form a network closely resembling that of a lymph gland with nuclei in the angles (_Plate VI, Fig. 6_). When the nodule softens, which takes place almost always exactly in the middle, it attains a brownish tint, which is due to the transparent softened part. If one divides the softened nodule, the central part has a distinct brown colour, and the constituents of this part readily fall out. If this is examined under a microscope, one sees, almost exclusively, larger or smaller clumps of a brownish colour, and very granular. They are partly elastic, but partly brittle and fragile, so that by pressure on the cover glass they are easily broken up. One often sees clearly that the clumps lie _in_ the cells, the nucleus and the cell substance being still evident (_Plate VII, Fig. 1_). Sometimes only one lies in a cell, which then has the appearance of a signet ring, in whose circle the clump lies, but sometimes several lie in one cell. One finds similar clumps in all other organs affected with leprosy, as in the liver, the spleen (_Plate VII, Fig. 2_), the nerves, lymphatic glands, the testicle and the eyes (_Plate VII, Fig. 3_, which shows two clumps from the retina). In the nodes of the skin, but particularly in the testicles, one may find them so large that they may even be seen by the naked eye. Both in the small and the larger clumps there are usually vacuoles, not infrequently several. From the cornea we have often got preparations in which the corneal corpuscles are more or less completely filled with brown granules (_Plate VIII, Fig. 1_). One sees here definitely the cell nucleus in the middle of the brown granular material.