. The American journal of anatomy. with nerve-fibers passing out into the mesenchyme from the latter. Theectoderm in the mid dorsal region dips down into the mesenchyme in theregion from which the brain was removed. X 45 diameters. Fig. 12. Experiment Sp, . Embryo of amblystoma killed 16 days afterhaving had the nasal pit of another embryo transplanted beneath the ecto-derm in the region dorsal to the right eye. Section through right eye andtransplanted nasal pit. Where the nasal pit is in contact with the outerlayer of the optic cup this portion of the outer layer is free from pigmentand in p
. The American journal of anatomy. with nerve-fibers passing out into the mesenchyme from the latter. Theectoderm in the mid dorsal region dips down into the mesenchyme in theregion from which the brain was removed. X 45 diameters. Fig. 12. Experiment Sp, . Embryo of amblystoma killed 16 days afterhaving had the nasal pit of another embryo transplanted beneath the ecto-derm in the region dorsal to the right eye. Section through right eye andtransplanted nasal pit. Where the nasal pit is in contact with the outerlayer of the optic cup this portion of the outer layer is free from pigmentand in places of greater thickness than normal. Between the nasal pit andectoderm are olfactory nerve-fibers. X diameters. Fig. 13. Experiment Sp,. Section through edge of nasal pit and ecto-derm showing the position of the olfactory nerve-fibers. Sections anteriorto this one show olfactory nerve-fibers passing from the nasal pit a shortdistance ventrally close to the median surface of the eye. X 180 diameters. Warren Harmon Lewis 469. 470 Evidence of the Outgrowth of the Axis Cylinder Fig. 14. Experiment DF^. Embryo rana palustris killed 4 days aftertransplantation of optic vesicle into position caudal to normal eye through transplanted eye showing formation of optic cup and courseof optic nerve from transplanted eye into medulla in the region of the Vnerve. The optic nerve passes through the marginal veil into the grey matterwhere the fibers become scattered and can only be followed for a few sec-tions anteriorly. The transplanted eye is separated from the ectoderm bymesenchyme and is without a lens. It is in contact with the 90 diameters. Fig. 15. Experiment DFi^. Embryo of rana palustris killed 5 days aftertransplantation of the optic vesicle into the region caudo-central to the oticcapsule. Section through anterior end of transplanted eye showing positionof optic nerve-fibers. The optic nerve is projected into this section in partfrom the adjoining sec
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1901
