(Part I) HISTOLOGICAL LESIONS IN THE NASAL CAVITY AND TEETH
Histological examination of the outer part of the nose and upper jaw of the severely infected animals presented the lesions in 51% of the nasal mucous membrane and 18% of the tooth pulp. The lesions were developing hematogenously along the connective tissue in the nose, as well as in the teeth, where they appeared more frequently and remarkably in the marrow of the alveoles and in the periodontium than the tooth pulp. From these results, it is supposed that the high frequency of lesions in the tooth pulp in human leprosy is due to the invasion of the bacilli along the nervous fibers.
(Part II) LESIONS AFTER INOCULATION THROUGH NASAL CAVITY AND TOOTH GUM
After the bacilli were rubbed in through nasal mucous membrane or the tooth gum, lesions appeared in higher percentages in the regional lymph nodes or the organs, such as the spleen or liver, rich in the reticuloendothelial tissue, than the local site, where slight lesions were found in very few cases. As the nasal mucous membrane is not the preditected site of murine leprosy, no primary lesion occurs even when the bacilli intrude there. And it seems possible that when the human bacillus infects the nasal mucous membrane, it can produce the primary lesion there.
(Part III) SUPPLEMENT TO THE DERIVATION OF THE MURINE LEPRA CELLS
The vital staining of trypan blue into the murine lesions of the lymph nodes informs us of the derivation of murine lepra cells from the histiocytes. The intraperitoneal inoculation of the bacilli shows that the wandering monocytes, although they have the phagocytosing power, do not permit the multiplication, while the phagocytic cells fixed in the tissue allow the multiplication of bacilli and transformed into lepra cells.
