The development of the human body; a manual of human embryology . Fig. 240.—Transverse Section Passing through the Otocyst (ot)of Embryos of (A) mm. and (B) 4 mm.—(His.) The mouth of each pit gradually becomes smaller, untilfinally the invagination is converted into a closed sac (, B), which separates from the surface ectoderm andbecomes enclosed within the subjacent mesoderm. Thissac is the otocyst, and in the stage just described, foundin embryos of 4 mm., it has an oval or more or less spheri-cal form. Soon, however, in embryos of mm., a pro-longation arises from its dorsal p
The development of the human body; a manual of human embryology . Fig. 240.—Transverse Section Passing through the Otocyst (ot)of Embryos of (A) mm. and (B) 4 mm.—(His.) The mouth of each pit gradually becomes smaller, untilfinally the invagination is converted into a closed sac (, B), which separates from the surface ectoderm andbecomes enclosed within the subjacent mesoderm. Thissac is the otocyst, and in the stage just described, foundin embryos of 4 mm., it has an oval or more or less spheri-cal form. Soon, however, in embryos of mm., a pro-longation arises from its dorsal portion and the sac as-sumes the form shown in Fig. 241, A; this prolongationrepresents the ductus endolymphaticus, and, increasing inlength, it soon becomes a strong club-shaped process, pro-jecting considerably beyond the remaining portions of the THE INTERNAL EAR. 461 otocyst (Fig. 241, B). In embryos of about sac begins to show certain other irregularities of shape(Fig. 241, B, sc). Thus, about opposite the point of originof the ductus endoly
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
