||P.615 left column 2nd paragraph: "[Researchers] also directly calculated the whole volume corresponding to all the structures from the external limit of the zona [zona pellucida, egg coat], for the stages prior to and following fertilization. No significant change was detected during fertilization-the whole volume of the metaphase II oocyte was 3.52±0.09×10^6µm^3 and the whole pronuclear embryo volume was 3.34±0.16×10^6µm^3 (P>0.05). Nor were significant differences observed after fertilization and successive developmental stages (whole oocyte volume 3.59±0.12×10^6µm^3 to whole 2-cell embryo 3.62±0.12×10^6µm^3. P>0.05 and whole 2-cell to 4-cell embryo 3.56±0.08×10^6µm^3. P>0.05)."