Archive image from page 49 of The development of the chick;. The development of the chick; an introduction to embryology . developmentofchi00lill Year: 1908 CHAPTER II THE DEVELOPMENT PRIOR TO LAYING I. Maturation The phenomena of the maturation and fertiUzation of the hen's egg are almost entirely unknown. The observations of Holl demonstrate only that the wall of the germinal vesicle tends to disappear when the follicle is nearly ripe. He also doubtfully identified six rod-shaped bodies at the margin of the germinal vesicle as the chromosomes of the maturation spindle (Fig. 8). Ch-. W0f- ',
Archive image from page 49 of The development of the chick;. The development of the chick; an introduction to embryology . developmentofchi00lill Year: 1908 CHAPTER II THE DEVELOPMENT PRIOR TO LAYING I. Maturation The phenomena of the maturation and fertiUzation of the hen's egg are almost entirely unknown. The observations of Holl demonstrate only that the wall of the germinal vesicle tends to disappear when the follicle is nearly ripe. He also doubtfully identified six rod-shaped bodies at the margin of the germinal vesicle as the chromosomes of the maturation spindle (Fig. 8). Ch-. W0f- ',p°' '=.♦5 ° J'oV<5y?ad''° o o iSo o- o 'o-V' Fig. 8. — Section of the germinal vesicle and surrounding parts of an ovarian ovum of the hen measuring 40 x 35 mm. (after Holl). Chr., Chromosomes. Gr., Granulosa. G. V., Germinal vesi- cle. Z. r., Zona radiata. But we have fortunately a very good account of the maturation and fertilization of the pigeon's egg by E. H. Harper, which fur- nishes the basis of the following description: The wall of the germinal vesicle begins to break down in ovarian eggs of about mm. diameter, the full size of the egg of the pigeon being about 25 mm. Part of the fluid contents of the germinal vesicle flows out and forms a layer outside the disinte- 32
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