. Cunningham's Text-book of anatomy. Anatomy. Fig. 95.—Frassi's Zygote. Estimated to be 18-19 days old (Bryce). The embryonic area is 1*17 mm. long and *6 mm. broad. Copied from Nor- maltafeln, Keibel and Elze, representing a recon- struction. The chorion is not shown. The upper part of the amnion is cut away, and the dorsal aspect of the embryonic area is seen from above. In the centre of the area is the neurenteric canal and caudal (inferior in the Fig.) to it is the primitive groove. Cephalwards of the neurenteric canal is the neural groove, in the middle of the neural plate. At the lower (
. Cunningham's Text-book of anatomy. Anatomy. Fig. 95.—Frassi's Zygote. Estimated to be 18-19 days old (Bryce). The embryonic area is 1*17 mm. long and *6 mm. broad. Copied from Nor- maltafeln, Keibel and Elze, representing a recon- struction. The chorion is not shown. The upper part of the amnion is cut away, and the dorsal aspect of the embryonic area is seen from above. In the centre of the area is the neurenteric canal and caudal (inferior in the Fig.) to it is the primitive groove. Cephalwards of the neurenteric canal is the neural groove, in the middle of the neural plate. At the lower (caudal) end of the Fig. is seen a section of the body stalk containing the allantoic diverticulum, and the nodulated area seen at the upper and right lateral part of the Fig. is a portion of the Fig. 96.—Spee's Zygote. (From Keibel and Elze's XormaUa/eln.) Length of embryonic area 1"54 mm. Estimated age 19-20 days (Bryce). At the lower end of the Fig. (caudal end of the embryo) is seen a portion of the chorion attached to the embryo by the body stalk. A portion of the amnion is still attached to the margin of the embryonic area, and the dorsal surface of the embryonic area is exposed. In the median plane of the area is the neural groove, and at the caudal end of the groove is the neur- enteric canal. The caudal part of the area is bent ventrally, and upon it is the remains of the primitive groove. The yolk-sac is seen at the upper and right part of the Fig. are present. The rudiments of the otic vesicles have appeared as slight depressions in the region of the hind-brain. The anterior and posterior neuropores are still open (Fig. 99). In the latter part of the fourth or the beginning of the fifth week the embryo attains a length of about 5 mm., when measured from the vertex of the head to the base of the tail, the mesodermal somites increase to thirty-five; the rudiments of the fore- and hind- limbs become quite distinct; the otic vesicles sink into the inte
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
