[Curing of the congenital osteopetrosis of "op" rats by thymus grafts]

A graft of normal thymus performed after thymectomy can cure the lethal osteopetrotic condition of the "op" Rat. The beneficial effect of normal bone marrow injection can be suppressed by prior thymectomy of the "op" Rat. Thymus is likely to play a role in the pathogenesis of osteopetrosis.