. The development of the human body : a manual of human embryology. Embryology; Embryo, Non-Mammalian. THE MEDULLARY FOLDS 73 canal (Figs. 43 and 45, nc) and is so called because it unites what will later become the central canal of the nervous system with the intestine (enteron). The significance of this canal has already been discussed (p. 58); it is of very brief persistence, closing at an early stage of development so as to leave no trace of its Fig. 45.—Diagram of a Longitudinal Section through the Embryo Gle, Meas- uring mm. in Length. al, Allantois; am, amnion; B, belly


. The development of the human body : a manual of human embryology. Embryology; Embryo, Non-Mammalian. THE MEDULLARY FOLDS 73 canal (Figs. 43 and 45, nc) and is so called because it unites what will later become the central canal of the nervous system with the intestine (enteron). The significance of this canal has already been discussed (p. 58); it is of very brief persistence, closing at an early stage of development so as to leave no trace of its Fig. 45.—Diagram of a Longitudinal Section through the Embryo Gle, Meas- uring mm. in Length. al, Allantois; am, amnion; B, belly-stalk; ch, chorion; h, heart; nc, neurenteric canal; V, chorionic villi; Y, yolk-sac.—(vonSpee.) As development proceeds the medullary folds increase in height and at the same time incline toward one another (Fig. 44), so that their edges finally come into contact and later fuse, the two ecto- dermal layers forming the one uniting with the corresponding layers of the other (Fig. 46). By this process the medullary groove be- comes converted into a medullary canal which later becomes the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original McMurrich, J. Playfair (James Playfair), 1859-1939. Philadelphia : P. Blakiston's son & co.


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Keywords: ., bookautho, bookcentury1900, bookdecade1910, booksubjectembryology