. The development of the frog's egg; an introduction to experimental embryology. Embryology. A B C Fig. 24. — Diagrams illustrating germ-ring and concrescence of lips of blastopore. As the dorsal lip of the blastopore progresses over the white hemisphere, its progress is due to the movement and fusion along a meridian of the material of the equatorial ring. AVe are to think of the material of the ring as moving toward the middle line from the right and left sides (for with the estab- lishment of the dorsal lip the ring becomes bilateral) and fusing continuously in the dorsal lip (Fig. 2-1). Th
. The development of the frog's egg; an introduction to experimental embryology. Embryology. A B C Fig. 24. — Diagrams illustrating germ-ring and concrescence of lips of blastopore. As the dorsal lip of the blastopore progresses over the white hemisphere, its progress is due to the movement and fusion along a meridian of the material of the equatorial ring. AVe are to think of the material of the ring as moving toward the middle line from the right and left sides (for with the estab- lishment of the dorsal lip the ring becomes bilateral) and fusing continuously in the dorsal lip (Fig. 2-1). The advance of the blastopore is merel}^ the expression of the absorption into its dorsal lip of the material of the two sides of the ring. As soon as the material from the sides reaches the median line in the dorsal lip of the blastopore, it remains stationary and new material is added behind that just laid down. The mate- rial of the equatorial ring is thus carried into a meridian of the egg. With the disappearance of the yolk-plug below 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 Morgan, Thomas Hunt, 1866-1945. New York, The Macmillan company; [etc. , etc. ]
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectembryology, bookyear1
