1. A practical method for the preparation and transplantation of whole epiphyseal plates in young rabbits is described.
2. Satisfactory survival with up to 80 per cent of normal growth for the twelve weeks of the experiment was achieved in half of the autografts; homografts survived and grew for four weeks and then were rejected apparently as a result of an atypical immune reaction.
3. The failures resulted from preventable technical errors. These included: (a) failure to include the germinal cells with the transplant, (b) inadequate supply of tissue fluid reaching the transplant, and (c) loose fit of the transplant in the recipient bed.