Abstract: | A morphological study of the spleen in the C57BL line female mice on the 16th day of pregnancy showed a significant increase in the relative area of generative centres and red pulp and a decrease in the white pulp relative area as well as a rise in the amount of plasmatic cells and blast forms in red pulp during allogenic pregnancy (BALB embryos). Such changes are supposed to favour both the preservation of the intact mother-extrafetal organs-fetus system and the improvement of allogenic embryos trophics. |