The effect of homograft sensitization of a mother against her fetuses has been studied. A female rabbit was repeatedly grafted from both members of a breeding pair. Their offspring should and do become objects of homograft sensitization induced in the female by grafts from the parents. After sensitization was established, fertilized ova were transplanted from the breeding pair to the sensitized female. At the same operation, an equal number of eggs was also transplanted to the same recipient from another breeding pair against which no sensitization had been induced. In 16 such families, the survival rates for offspring born of each type of egg were found to be almost identical, indicating that homograft sensitization in the mother directed against her fetuses did not demonstrably harm them.