BBCT. 203.] THE GRAAFIAN FOLLICLES. 45 I 



the two surfaces and the free border of the organ, so that a 

 pencilliform figure appears on a transverse section. The ovi- 

 capsules, or ovi-sacs, usually called Graafian vesicles (folliculi ovarii 

 s.f. Graafiani s.ovi-sacci), are little round sacs, \"' to 3'" in average 

 size, and closed on all sides (fig. 183, a b). They are imbedded in 

 the more peripheral parts of the stroma, so that a section of the 

 parenchyma of a well-developed and normal ovary maybe described 

 as dividing into a medullary and cortical substance, the latter alone 

 containing the follicles. "We must be careful to obtain healthy 

 and well-developed ovaries, if we would obtain a correct view of 

 the size, position, and number of the Graafian follicles. Their 

 number will be found to amount from 30, 50 to 100 in each ovary, 

 and may, in many cases, reach up to 200 ; while in stunted or 

 degenerated ovaries, such as are frequently seen especially in old 

 women, we may meet with but few (between two and ten, for 

 example), or there may even be none at all. 



In its fully-developed condition, each follicle consists of coverings 

 and contents. The former can be compared most suitably to a 

 mucous membrane, and presents the fol- 



1 Fis\ 184. 



lowing elements : 1. The tunica fibrosa, or 

 theca folliculi of v. Baer, a fibro-vascular 

 laver of considerable relative thickness, 

 which is connected with the stroma of the 

 ovary by somewhat loose tissue, and, con- 

 sequently, is easily separable as a whole. 

 The outer laver of this membrane, which 

 is somewhat firmer, and reddish-white in 

 colour (fig. 184, a), is distinguished bv G ™>fi™ foiucie of t he pig, 



v D ™ I' a j magnified about 10 times, a. 



v. Baer from the inner lamina, which is °, nter ' b - lnne Jv I 1:i ^ r „.°, f the 



hbrous coat ot the follicle ; c. 



thicker, softer, and more distinctly red in membra™ granulosa; a. .liquor 



J folliculi; e. germiu.il eminence, 



hue (fig. 184, b) : but, it is to be remarked, a paction of the membrana 



•' ' * ' ' granulosa;/, ovum, with zona 



that the inner laver also can be split into peiiucida, yeik, and germinal 



" r vesicle. 



two parts, and that both the outer and the 



inner lamina? consist of the same nucleated connective tissue, un- 

 developed and interspersed with numerous, mostly fusiform, forma- 

 tive cells. A delicate structureless membrana propria forms the 

 inner boundary of the fibrous tunic in young follicles, and even, 

 subsequently, can often be demonstrated as a special membrane, 

 by the action of alkalies. 2. An epithelium — the granular layer, 

 or membrana granulosa of authors (fig. 184, c). This membrane 

 is o'oo8'" to 0012'" and upwards in thickness, lines the whole 

 follicle ; on the side turned towards the surface of the ovary, 



G G 2 



