. The development of the human body : a manual of human embryology. Embryology; Embryo, Non-Mammalian. 28 THE MATURATION OF THE OVUM although female monkeys menstruate regularly throughout the year, nevertheless there is but one annual cestral period when ovulation takes place (Heape). The Maturation of the Ovum.—Returning now to the ovum, it has been shown that at the time of its extrusion from the Graafian follicle it is not equivalent to a spermatozoon but to a primary spermatocyte, and it may be remembered that such a spermatocyte. Fig. 14.—Ovum of a Mouse Showing the Maturation Spindle. T
. The development of the human body : a manual of human embryology. Embryology; Embryo, Non-Mammalian. 28 THE MATURATION OF THE OVUM although female monkeys menstruate regularly throughout the year, nevertheless there is but one annual cestral period when ovulation takes place (Heape). The Maturation of the Ovum.—Returning now to the ovum, it has been shown that at the time of its extrusion from the Graafian follicle it is not equivalent to a spermatozoon but to a primary spermatocyte, and it may be remembered that such a spermatocyte. Fig. 14.—Ovum of a Mouse Showing the Maturation Spindle. The ovum is enclosed by the zona pellucida (), to which the cells of the corona radiata are still attached.—(Sobotta.) becomes converted into a spermatozoon only after it has undergone two divisions, during which there is a reduction of the number of the chromosomes to practically one-half the number characteristic for the species. Similar divisions and a similar reduction of the chromosomes occur in the case of the ovum, constituting what is termed its maturation. The phenomena have not as yet been observed in. 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 McMurrich, J. Playfair (James Playfair), 1859-1939. Philadelphia : P. Blakiston's son & co.
Size: 1541px × 1621px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookautho, bookcentury1900, bookdecade1910, booksubjectembryology
