There are 5 stages during the development of embryo, including the stage of 2-celled proembryo, multicellular proembryo, globular proembryo, pyriform proembryo, differential embryo and mature embryo.

胚胎发育经过二细胞原胚、多细胞原胚、球形原胚、梨形原胚、分化胚和成熟胚阶段。