1. Autotransfusion and cross-transfusion experiments in the turkey reveal that the avian erythrocyte, despite the presence of a nucleus, survives normally in homologous recipients of compatible blood groups.
2. Skin homografts were rejected without apparent relationship to blood group compatibility.
3. Evidence for blood groups in the turkey is presented. While no naturally occurring iso-agglutinins were found, stimulation led to the appearance of incomplete antibodies.