Under light microscope the diameter of YSP and the scoring of blood circulation were found to be on the decline and the incidence of terata increased with the increasing concentration of arsenic and methylmercury .

光镜下卵黄 囊 胎盘直径和血管 分化得分值逐渐下降， 畸胎率随着 给 药浓度的增加而不断升高，呈剂量-反应关系；