trophosphere (trofosfer)

[ nourishment, + βλαστός, a germ.] An external epiblastic layer that does not enter into the formation of the embryo, but does take an active part in nutritional proce es intended for it; the blastocystic ectoderm. a zone of modified cellular ti ue interposed between the decidual stroma and the blastocyst, formed of the trophoblastic (embryonal) and trop hos pong i an (maternal) layers. It is so called in Erinaceus, where it is of a spherical shape, but in other mammals it may be called trophodisk, trophocalyx, IMG:content-0941.png:[blocks in formation]