An autotransplantation of fresh rib in mandibular bone of Japanease monkey (3 years old) was performed and the effect of bone transplantation on living body was immunolo gically investigated by extracting the left and right submandibular lymph node, the spleen and the soft tissue around the transplanted region. In the case of lymph node and spleen, the transplantation of T and B cell were examined by using Rosette method. The tissue around the transplanted region was pathologically investigated. The results obtained were as follows : 1. The reactive inflammation of soft tissue was the most progressive after 5 days from operation. In addition, the creation of young granulation tissue and some new-growth of capillary vessel were recognized in the soft tissue. The phylogocytes were begun to reduce from 7th day after the operation and completely disappeared in 14th day. The soft tissue after 14 days from transplantation was filled up by new-growth vessels and young granulation tissue. 2. The number of T cell in submandibular lymph node of nontransplanted side begun to decrease at 5th day from transplantation. On the other hand, the number of B cell began to increase at 3rd day from transplantation and reached the normal value at 5th day. 3. The number of T cell in submandibular lymph node of transplanted side of bone reached the maximum value at 1st day and began to decrease from 3rd day and reached the normal value at 7th day after bone transplantation. The B cell rapidly increased at 1st day from transplantation and reached in maximum numbers. After 7 days, the number of B cell diminished gradually and reached the normal value at 14th day. 4. The number of T cell in spleen gradually increased from one day after operation and reached the maximum value at 14th day. The number of B cell decreased for 14 days and reached the normal value after 14th day. 5. The vital reaction after bone transplantation was closely related to the reactive inflammation in soft tissue (in submandibular lymph nodes) and the variation of spleen.
