. The elements of experimental embryology. Embryology, Experimental; Embryology. Fig- 51 The polar lobe in Dentalium. a. Fertilised egg with animal and vegetative clear zones (pole plasms), b, Protrusion of first polar lobe. c,It passes to one of the first two blastomeres. d, 2-cell stage, retraction of polar lobe, e, 2-cell stage, pro- trusion of second polar lobe. /, End of second cleavage, second polar lobe passes to the D blastomere. (After Wilson, from Morgan, Experimental Embryology, Columbia University Press, 1927.) diflferent blastomeres, a larva with a fixed number of cells is pro- du
. The elements of experimental embryology. Embryology, Experimental; Embryology. Fig- 51 The polar lobe in Dentalium. a. Fertilised egg with animal and vegetative clear zones (pole plasms), b, Protrusion of first polar lobe. c,It passes to one of the first two blastomeres. d, 2-cell stage, retraction of polar lobe, e, 2-cell stage, pro- trusion of second polar lobe. /, End of second cleavage, second polar lobe passes to the D blastomere. (After Wilson, from Morgan, Experimental Embryology, Columbia University Press, 1927.) diflferent blastomeres, a larva with a fixed number of cells is pro- duced. In Dentalium, at the approach of the first cleavage, a portion of the vegetative region is partially constricted off from the rest of the egg as the so-called polar lobe. This passes to one of the first two blastomeres and is then withdrawn into it. The blastomere with the polar lobe is destined to be posterior, and is called CD in con- tradistinction to the AB or anterior blastomere (figs. 51, 52).. 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 Huxley, Julian, 1887-1975; De Beer, Gavin, Sir, 1899-1972. New York [Hafner Pub. Co. ]
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Keywords: ., bookcentury1900, bookcollectionbiodiversi, booksubjectembryology
