Fig. 20. Section through part of an ovary of the same embryo as fig. 6, containing a nest of nuclei. Zeiss F, ocul. 2. Osmic acid.
Fig. 21. Ovum from the ovary of a half-grown female, containing isolated deeply stained patches of developing yolk granules. Zeiss B, ocul. 2. Picric acid.
Fig. 22. Section through a small part of the ovum of an immature female of Scyllium canicula, to shew the constitution of the yolk, the follicular epithelium, and the egg membranes. Zeiss E, ocul. 2. Chromic acid.
Fig. 23. Section through part of the periphery of a nearly ripe ovum of Scy. canicula. Zeiss C, ocul. 2. It shews the remnant of the vitelline membrane (v.t.) separating the columnar but delicate cells of the follicular epithelium (f.e.) from the yolk (yk.). In the yolk are seen yolk-spherules in a protoplasmic network. The transverse markings in the yolk-spherules have been made oblique by the artist.
Fig. 24. Fully formed ovum containing a second nucleus (x), probably about to be employed as pabulum; from the same ovary as fig. 5. The follicular epithelium is much thicker on the side adjoining the stroma than on the upper side of the ovum. Zeiss F, ocul. 2. Osmic acid.
Fig. 25. A. Ovum from the same ovary as fig. 21, containing in the yolk three peculiar bodies, similar in appearance to the two small bodies in the germinal vesicle. B. Germinal vesicle of a large ovum from the same ovary, containing a body of a strikingly similar appearance to those in the body of the ovum in A. Zeiss E, ocul. 2. Picric acid.
Fig. 26. Section of the ovary of a young female of Scyllium stellare 16½ centimetres in length. The ovary is exceptional, on account of the large size of the stroma ingrowths into the epithelium. Zeiss C, ocul. 2. Osmic acid.
Fig. 27. Ovum of Scyllium canicula, 5 mm. in diameter, treated with osmic acid. The figure illustrates the development of the yolk and a peculiar mode of proliferation of the germinal spots. Zeiss A, ocul. 2.
Fig. 28. Small part of the follicular epithelium and egg membranes of a somewhat larger ovum of Scyllium canicula than fig. 22. Zeiss D D, ocul. 2.
Fig. 29. The same parts as in fig. 28, from a still larger ovum. Zeiss D D, ocul. 2.