. The primitive streak and notochordal canal in Chelonia. Embryology; Chelonia (Genus). Regression of the Neurenteric Canal along the Streak. 41 space they enclose equals in width the lateral extent of the open portion of the blastopore. Indeed, these two depressions are the posterior extensions or horns of the crescentic portion of the open blastopore. As this process of sinking continues, the central area by degrees falls lower and lower, until it reaches the level of the floor of the notochordal canal, at which level it disappears. That portion which is going to form the dorsal wall of the
. The primitive streak and notochordal canal in Chelonia. Embryology; Chelonia (Genus). Regression of the Neurenteric Canal along the Streak. 41 space they enclose equals in width the lateral extent of the open portion of the blastopore. Indeed, these two depressions are the posterior extensions or horns of the crescentic portion of the open blastopore. As this process of sinking continues, the central area by degrees falls lower and lower, until it reaches the level of the floor of the notochordal canal, at which level it disappears. That portion which is going to form the dorsal wall of the archenteron passes laterad and upward to fuse again in the dorsal lip, while that portion which forms the floor of the potential archenteron will disintegrate in order to put this cavity into communication with the yolk. These successive stages in the sinking of the streak behind the neurenteric canal, and its subsequent elevation and refusion an- terior to this canal can be traced in a series of sections made through the streak of an embryo whose blastopore has become ^^i^m^ })Kee'd?)n. _Jk ^i(^Tnesc(im. II. en'drin. hj -nkU. ) \T'-*"' J5P^\I ••-. --i£^lei" 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 Davenport, Gertrude Anna (Crotty) 1866-. Boston, Ginn
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectembryology, bookyear1
