OVARY. 121 



(H). Study each of these parts from within outwards. In the vitellus, yolk-granules and 

 a fine reticulum of fibres may be detected. 



Study a Small, Unripe, Graafian Follicle. (H). These are found near the surface of the 

 section. Notice the ovum, with a relatively thin zona pellucida, and the membrana granulosa, 

 consisting of, perhaps, only two layers of cells, and not yet separated into two distinct layers 

 by the appearance of the liquor folliculi between them. All gradations are found between 

 these and a follicle ready to burst and discharge its ovum. (Indicate these, and tlie epitlielium 

 covering t/ie ovary, in PI. XXIX., Fig. 2.) 



THE DEVELOPMENT OF GRAAFIAN FOLLICLES AND OVA. 



The ovaries of foetal kittens or rabbits are prepared in the same way as directed for the 

 adult ovary (p. 120). Sections show the development of the ova from the germinal epithelium 

 covering the ovary. 



/ / 7/> 







Rg. 



CORPORA LUTEA. 



These are easily studied in the ovary of a cow, where they are very large. Small pieces of 

 one of them ought to be macerated in very dilute potassic bichromate, to isolate the large 

 branched and pigmented cells which compose them. Coloured crystals of haematoidin may be 

 found. Other pieces ought to be hardened in Miiller's fluid for two weeks, and sections made 

 to study the arrangement of the cells which compose them. 



THE FALLOPIAN TUBE. 



PREPARATION. Cut the Fallopian tube of a cat or bitch into pieces an inch long, and 

 harden them for four days in the chromic acid and spirit mixture. Make transverse sections, 

 and stain them with logwood, and mount them in dammar. 



EXAMINATION (L and H). Observe the serous, or outer coat, composed of fibrous tissue, 

 and within this the muscular coat, composed externally of a few muscular fibres, arranged longi- 

 tudinally, and therefore cut transversely, whilst within these is a much thicker circular coat. 

 Then follows the mucous coat, consisting of fibrous tissue, containing many blood-vessels. 

 It is thrown into longitudinal folds by the contraction of the circular muscular fibres, and is 

 lined by columnar ciliated epithelium. It contains no glands. Do not mistake the depressions 

 between the folds of the mucous membrane for glands. (Indicate part of the wall of tfie tube in 

 PI. XXIX., Fig. 5.) 



THE UTERUS. 



PREPARATION. Remove the uterus from a cat or bitch preferably from an animal 

 which has borne young cut it in pieces an inch long, and harden them for five days in chromic 

 acid and spirit mixture, and then transfer them to spirit. Make transverse sections, and stain 

 them with logwood, and mount them in dammar. 



R 



