BY DR. KLEIN. 147 



be steeped for a short time in concentrated solution of chloride 

 of potassium. Instead of the carmine, solution of sulpho- 

 indigotate of soda, saturated in the cold, may be used in 

 exactly the same manner. The bloodvessels must, however, 

 be subsequently injected, not with Prussian blue, but with 

 carmine gelatin. 



Pelvis, Ureter, and Bladder. The laminated epithe- 

 lium of these parts may be studied in bichromate of potash 

 preparations. For sections, the membrane must be hardened 

 in chromic acid. The methods for the study of the epithelium, 

 muscular tissue, nerves, and ganglia, etc., have been already 

 fully described in Part I. 



SECTION III. GENITAL OKGANS. 



Epithelium and Endothelium of Ovary. It has 



been recently shown by Waldeyer that the ovary is only 

 partly covered with peritoneum. Where this is the case the 

 surface is covered with endothelium. The remainder of the 

 surface possesses a cylindrical epithelium, to which the term 

 germinal epithelium is applied. This can be demonstrated in 

 the ovaries of the sow, bitch, and cat, and in the human 

 ovary. In the last it can be seen both in the mature foetus 

 and in the adult. In the fresh ovary the line of demarcation 

 can be made out, even with the naked eye. By scraping the 

 surface with a scalpel, shreds can be obtained which may be 

 at once prepared in salt solution. In those taken from the 

 peritoneal part, large endothelial plates can be shown, each 

 containing an oblong nucleus. In those from the other part, 

 cylindrical cells are seen, which consist of distinctly granular 

 protoplasm, and contain an ovoid rucleus and nucleolus. 

 These possess the character of epithelial elements. If an 

 ovary is placed a few minutes in silver solution and then 

 washed the usual way in water, and hardened in alcohol, 

 sections parallel with the surface of both parts may be pre- 

 pared. In such sections, if made close to the surface, and 

 covered in glycerin, the contrast between the two forms of 

 cellular investment can be completely demonstrated. 



The anatomical relations of the germinal epithelium, and of 

 the tunica albuginea, stroma, and Graafian vesicles must be 

 studied in sections. For this purpose the fresh organ obtained 

 from any of the above-mentioned animals must be steeped in 

 one or two per cent, solution of bichromate of potash for 

 periods varying from four days to a week ; it must then be 

 transferred for a day or two to one-eighth or one-tenth per cent, 

 solution of chromic acid, and can afterwards be kept in com- 

 mon alcohol. Small ovaries, such as those of mature foetuses, 

 or of other young animals, can be embedded in toto. Larger 

 organs must be divided. 



