Tissue Specificity in Embryonic and Adult Cymatogaster Aggregata Studied by Scale Transplantation

Embryonic and adult Cymatogaster aggregata have been subjected to scale homotransplantations.2. Homografts are rejected after a short period of time. The time required for graft rejection is temperature-dependent.3. Increased sensitivity to homografts results from successive transplantations.4. Intra-ovarian embryos used in these experiments were not capable of rejecting scale homografts.5. Immature free-living fish rejected homografts, but more slowly than adults.6. Pregnant females can transfer homograft sensitivity to intra-ovarian embryos. It is hypothesized that circulating antibody is passed to the embryo via the ovarian fluid and the embryonic hindgut.