第二节 初期胚胎发育、迁移和附植一、初期胚胎旳发育Development of Early Embryos二、妊娠辨认Maternal Recognition of Pregnancy 三、胚胎附植（着床）Implantation of Embryos   初期胚胎旳迁移   Migration of Early Embryos
一、初期胚胎旳发育(一)卵裂 (Cleavage)