Embryonic development of the mouse, with reference to intrauterine position

The degree of development of embryos in the same litter varied. In both the control and the experimental group the foetal weight curve followed a U-shaped course, with the lightest embryos in the intermediate position. A high incidence of split-face embryos was found in the lateral (ovarian) position in the uterus, while the highest frequency of exencephalic embryos occurred in the intermediate position.