. The anatomy of the domestic fowl . Domestic animals; Veterinary medicine; Poultry. EMBRYOLOGY OF THE CHICK 319 Oogenesis.âThe ovum during its formation passes through three stages. The first stage, that of division, takes place before the chick is hatched, and, according to Bradley, comes to an end about the time of hatching. This stage consists of the rapid formation of ova in the female chick. In the second stage, which begins about the time of hatching, there is an increase in the size of the units of the ovary, accompanied by yolk formation. At this time each ovum is in its own follicle
. The anatomy of the domestic fowl . Domestic animals; Veterinary medicine; Poultry. EMBRYOLOGY OF THE CHICK 319 Oogenesis.âThe ovum during its formation passes through three stages. The first stage, that of division, takes place before the chick is hatched, and, according to Bradley, comes to an end about the time of hatching. This stage consists of the rapid formation of ova in the female chick. In the second stage, which begins about the time of hatching, there is an increase in the size of the units of the ovary, accompanied by yolk formation. At this time each ovum is in its own follicle (Fig. 81), and is surrounded by a layer of cuboidal cells and a theca. The theca is formed from the adjacent fibrous. Pig. 81.âSection of ovum in a hen. i. Nucleolus. 2. Nucleus. 3. Liquor folliculi. 4. Stratiun granulosum. 5. Follicular cells. 6. Theca foUiculi. 7. Peripheral stroma. stroma. The third stage, that of maturation, commences during the development of the yolk and is complete after it has escaped to the â oviduct. Maturation consists of each cell's dividing into two un- equal parts. In each division the cell is spUt into a smaU ceU known as the polar body, which is cast off and disappears, and a larger cell, which is the ovum proper. In this process half of the original chromosomes are cast off. Fertilization.âThe sperm travels rapidly; experiments have shown eggs to be fertile laid twenty-four hours after service by a 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 Kaupp, Benjamin Franklyn, 1874-. Philadelphia ; London : W. B. Saunders Company
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectpoultry
