Numbers of metrial gland cells in the placental labyrinth of congenic resistant and inbred strains of mice, with observations on the size of the labyrinth.

The size of the placental labyrinth and the number of metrial gland cells in it were investigated, from the eleventh to the sixteenth day of gestation, in C57BL/10Sn, B10.A/SgSn, SWR/J and DBA/2J isogenic matings and C57BL/10Sn X B10.A/SgSn and B10.A/SgSn X C57BL/10Sn congenic matings. It was found that both H-2 disparity between mother and conceptus and some other strain-specific trait under genetic control influence the size of the placental labyrinth, while the number of labyrinthine metrial gland cells is affected only by the strain-specific trait.