. Breeding farm animals. Livestock; Breeding. THE GERM CELLS 0/. FIG. 6.—THE FERTILIZATION OF THE EGG.—A, egg surrounded by spermato- zoa; on the right, one has just penetrated the egg membranes and is enter- ing the egg cytoplasm; egg nucleus in the center. B, egg nucleus with chromatin reticulum on left; on right, the sperm nucleus preceded by its centrosome and attraction sphere. C, egg nucleus on the left, sperm nucleus on the right of the center of the egg; stage immediately preceding the divi- sion of the centrosome. D, the centrosome has divided, the two attraction spheres separate to f
. Breeding farm animals. Livestock; Breeding. THE GERM CELLS 0/. FIG. 6.—THE FERTILIZATION OF THE EGG.—A, egg surrounded by spermato- zoa; on the right, one has just penetrated the egg membranes and is enter- ing the egg cytoplasm; egg nucleus in the center. B, egg nucleus with chromatin reticulum on left; on right, the sperm nucleus preceded by its centrosome and attraction sphere. C, egg nucleus on the left, sperm nucleus on the right of the center of the egg; stage immediately preceding the divi- sion of the centrosome. D, the centrosome has divided, the two attraction spheres separate to form the first cleavage spindle; the chromosomes of the egg and sperm nuclei clearly visible and indistinguishable (in the figure the egg chromosomes are black, the sperm chromosomes shaded). E, the first cleavage spindle, with splitting of chromosomes. F, completion of first cleav- age; two-celled Stage, each nucleus contains four chromosomes—two from the egg and two from the sperm. (After Boveri.) Reproduced from Jordan's "Foot-Notes to Evolution," by permission of D. Appleton & 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 Marshall, F. R. Chicago, The Breeder's gazette
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectlivestock, bookyear19
