. The cell in development and inheritance. Cells. O OOpho^. Fig. 141. — First type of maturation in the parthenogenetic egg oi Arfemia. [BraUER.] A. The first polar spindle; the equatorial plate contains 84 tetrads. B. C. Formation of the first polar body; 84 dyads remain in the egg, and these give rise to the egg-nucleus, shown in D. F. Appearance of the egg-centrosome and aster. E. G. Division of the aster and formation of the cleavage-figure; the equatorial plate consists of 84 apparently single but in reality bivalent chromosomes. this arise eighty-four thread-like chromosomes, and tJie sa
. The cell in development and inheritance. Cells. O OOpho^. Fig. 141. — First type of maturation in the parthenogenetic egg oi Arfemia. [BraUER.] A. The first polar spindle; the equatorial plate contains 84 tetrads. B. C. Formation of the first polar body; 84 dyads remain in the egg, and these give rise to the egg-nucleus, shown in D. F. Appearance of the egg-centrosome and aster. E. G. Division of the aster and formation of the cleavage-figure; the equatorial plate consists of 84 apparently single but in reality bivalent chromosomes. this arise eighty-four thread-like chromosomes, and tJie same number appears in later cleavage-stages. (b) It is the second and rarer mode that realizes Boveri's concep- tion (Fig. 142). Both polar bodies are formed, the first removing eighty-four dyads and leaving the same number in the egg. In the formation of the second, the eighty-four dyads are halved to form. 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 Wilson, Edmund B. (Edmund Beecher), 1856-1939. New York, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcells, bookyear1911
