. A laboratory manual and text-book of embryology. Embryology. 20 THE GERM CELLS: MITOSIS, MATURATION AND FERTILIZATION in number during the growth of the ovum until several layers surround it (Fig. 3). A cavity appearing between these cells becomes filled with fluid and thus forms a sac, the Graafian follicle, within which the ovum is eccentrically located. The cells of the Graafian follicle immediately surrounding the ovum form the corona radiata (Fig. 1) when the ovum is set free. Ovulation and Menstruation.—When the ovum is ripe, the Graafian follicle is large and contains fluid, probably
. A laboratory manual and text-book of embryology. Embryology. 20 THE GERM CELLS: MITOSIS, MATURATION AND FERTILIZATION in number during the growth of the ovum until several layers surround it (Fig. 3). A cavity appearing between these cells becomes filled with fluid and thus forms a sac, the Graafian follicle, within which the ovum is eccentrically located. The cells of the Graafian follicle immediately surrounding the ovum form the corona radiata (Fig. 1) when the ovum is set free. Ovulation and Menstruation.—When the ovum is ripe, the Graafian follicle is large and contains fluid, probably under pressure. The ripe follicles form bud-like projections at the surface of the ovary (Fig. 5), and at these points Ovum Follicle cells *© «. Zowa pclluclda Fig. 6.—Immature follicle containing several ova. From the ovary of a young monkey. X 43°- the ovarian wall has become very thin. It is probable that normally the bursting of the Graafian follicle and the discharge of the ovum are periodic and associated with the phenomena of menstruation. That ovulation or discharge of the ovum from the ovary may occur independent of the menstrual periods has been proven by the observations of Leopold. Also in young girls ovulation may precede the inception of menstruation and it may occur in women some time after the menopause. At birth, or shortly after, all of the ova are formed in the ovary of the female. 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 Prentiss, Charles William, 1874-1915. Philadelphia, London, W. B. Saunders
Size: 2122px × 1178px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
