. Journal of anatomy . rmine. It may be supposed, for the sake of argument, thatthe embryo accomplishes implantation by reason of an assimilative actionon the part of its outermost cells, comparable to the methods by which theamoeba is capable of assimilating its nutrition. Were this so, we should be Embedding of the Embryo Guiiiea-Pig in the Uterine Wall 199 prepared to find elongated processes from the embryonic cells extending tothe uterine cells, in the manner of amrebic processes, there coalescing and atthe same time enveloping portions of maternal protoplasm. Also we shouldexpect to see
. Journal of anatomy . rmine. It may be supposed, for the sake of argument, thatthe embryo accomplishes implantation by reason of an assimilative actionon the part of its outermost cells, comparable to the methods by which theamoeba is capable of assimilating its nutrition. Were this so, we should be Embedding of the Embryo Guiiiea-Pig in the Uterine Wall 199 prepared to find elongated processes from the embryonic cells extending tothe uterine cells, in the manner of amrebic processes, there coalescing and atthe same time enveloping portions of maternal protoplasm. Also we shouldexpect to see the maternal tissues retaining full vigour except at the areain immediate contact with the cells of the embryo. On the other hand, itmay be suggested tliat implantation results from a digestive action on thepart of the embryonic cells: from a digestive secretion or enzyme producedby these cells reacting upon the maternal tissues. In support of this con-tention we have the demonstration in embryo No. 1 of the commencing. PhotomickogkaiH No. 5.—A very high magnification of embryo No. 5 .show-ing the embr3o, a mass of undifferentiated cells, surrounded on its freesurface b} zona pellucida, in direct contact with the stroma of connectivetissue cells ; near the uj)per pole a cell of the embryo is seen protruding intothe uterine epithelium. Vacuolation of the connective tissue stroma is seen. disintegration of the uterine epithelium, although the embryo is, in thisparticular section, still at an apprecialile distance from the uterine wall;and also the demonstration, in embryos Nos. 2, 4, 5, and 6, of vacuolatedareas in the maternal tissues in the vicinity of the implantation sites,sufficiently remote from the embryonic cells to lead us to believe thatthe action of these cells is by no means confined to the tissues in tlieimmediate vicinity. Although, in the photomicrographs 4, 5, and (i of (?inbr\os Nos. 5 200 d E. Emrjs-Roberts and 6, there is to be seen a cell in each of th
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectanatomy, bookyear1867
