162 J. T. CUNNINGHAM. 



Fig. 19. — A dead aborted ovum, from a section of the ovary of a plaice 

 11| in. long, obtained in Grimsby market August 3rd, 1895. Pixed in 

 chromic acid ^ per cent. Stained with Mayer's hsemalum. /. e. Follicular 

 epithelium, g. v. Germinal vesicle in altered condition, showing one large 

 nucleolus. 



Fig. 20. — Ova from the ovary of a plaice 12J in. long, examined in the 

 fresh condition September 21st, 1895, at Lowestoft. The largest ovum has 

 just died at a stage when the formation of yolk has scarcely commenced. 

 g. V. Germinal vesicle. 



Fig. 21. — Two ova from section of the ovary of a flounder 11 in. long, 

 taken from Plymouth aquarium July 11th. Fixed in Flemming's strong 

 mixture. Stained with safranin. Zeiss F, oc. 3. v. n. Vitelline nucleus. 



Fig. 22. — Portion of a section of an ovary of Syngnathus acus, fixed 

 with chromic acid y^ per cent, and picric acid 40 per cent. Stained with 

 safranin, gentian violet, and orange G. Zeiss A, oc. 3. g. e. Germinal 

 epithelium at the edge of the ovarian lamella, v. n. Vitelline nuclei. 



Fig. 23. — Ovum •049 mm. diameter, from the section shown in Fig. 22, 

 showing the vitelline nucleus in contact with the germinal vesicle. Zeiss E, 

 oc. 3. V. n. Vitelline nucleus. 



Fig. 24. — The germinal vesicle of an ovum '27 mm. diameter, in section 

 of the ovary of a plaice from which Fig. 14 is taken. In this ovum yolk- 

 formation had not commenced. Zeiss, apochr. immersion, 2 mm., compens. 

 oc. 8. ch. Feathery fibrils, the chromosomes of Ruckert. n. Nucleoli. 



Fig. 25. — Ova from the ovary of a plaice 13J in. long, examined in the 

 fresh condition September 16th. The formation of yolk has just commenced 

 in the largest ovum, which also shows the wrinkled or mulberry-like form of 

 the membrane of the germinal vesicle. Zeiss C C, oc. 3. 



Fig. 26. — Germinal vesicle of an ovum '39 mm. in diameter, from the same 

 series of sections from which Fig. 14 is taken. Zeiss E, oc. 3. ch. Central 

 fibrils, n. Nucleoli. 



PLATE 4. 



Fig. 27. — Germinal vesicle of an ovum '36 mm. in diameter, from the same 

 series of sections from which Fig. 15 is taken, ch. Central fibrils, n. 

 Nucleoli. 



Fig. 28. — Germinal vesicle of an ovum "46 mm. in diameter, in a section 

 from the ovary of a turbot 2 ft. IJ in. long. Fixed with picro-sulphuric 

 acid and spirit. Stained with haemalum. Zeiss C C, oc. 3. 



Fig. 29. — Germinal vesicle of an ovum "39 mm. in diameter, from the same 

 series of sections as Fig. 28. Zeiss E, oc. 3. n. Nucleoli in the form of 

 rods of various shapes. 



