Early development and implantation of the blastocyst in the bat,Hipposideros speoris (Schneider)—Hipposideridae—Microchiroptera
The embryo ofHipposideros speoris enters the uterus at the morula stage of development. The blastocyst implants superficially and circumferentially and the embryonic mass is so oriented during implantation that it faces between the antimesometrial and the lateral sides of the uterus. The most conspicuous progestational change in the uterus concerns the uterine glands which undergo hypertrophy and become wide thereby reducing the endometrial stroma to thin strands. During implantation the glands undergo destruction, accompanied by the destruction of endometrial cells, and the formation of symplasma. The trophoblast on the embryonic hemisphere is more invasive than that in the other regions of the blastocyst.