THE FEMALE GENITAL OEGAN8. .873 



suspended from the sublumbar region, where they correspond with the 

 intestinal convolutions, a little behind the kidneys. Smooth on the surface, 

 these organs present, iii the middle of their upper face, a deep, and more or 

 less oblique fissure, resembling the Tiilus of the kidney ; this gives attach- 

 ment to the pavilion of the tube. 



Means of attachment. The ovary floats at the anterior border of the 

 broad ligament ; it is also sustained by the vessels which enter it, and by a 

 small cord of unstriped muscular fibres, the ligament of the ovary, which 

 attaches it to the uterus. 



STRUCTURE. The organisation of the ovaries comprises a serous mem- 

 brane, a tunica albuginea, proper tissue, and the Graafian vesicles imbedded 

 therein. 



Serous membrane. This is a continuation of the broad ligaments ; it 

 covers the whole organ (except at the hilus), adhering closely to the tunica 

 albuginea. 



Tunica albuginea. This is similar to that enveloping the testicle, being 

 a very resisting fibrous case which sends prolongations into the substance of 

 the ovary. 



Proper tissue. The proper tissue, or stroma, of the ovary is more con- 

 sistent than that of the testicle ; it is hard, grates on being cut into, and 

 is greyish-red in colour. It is divisible into two layers, distinguishable by 

 their aspect and structure. 



1. The medullary layer, that nearest the hilus, is slightly red and 

 spongy ; it is formed by an interlacing of the connective fibres, unstriped 

 muscular fibres, and a large number of vessels that radiate from the centre 

 towards the periphery. 



2. The cortical layer has the elements of connective tissue for its base; 

 it is but little vascular, and contains in its substance the Graafian vesicles 

 or follicles (ovisacs), and is consequently often named the ovigenous layer. 

 These ovisacs are in various stages of development ; the smallest are 

 situated beneath the tunica albuginea, and gradually increase as they lie 

 deeper. When fully developed, they are filled with a transparent, citron- 

 coloured fluid ; the ovigenous layer can then no longer contain them, and 

 they protrude more or less from the surface of the ovary. 



A Graafian vesicle, in its perfect state, is composed of an envelope and 

 its contents. The envelope comprises: & fibrous membrane (tunica fibrosa), 

 which is confounded with the stroma of the ovary, and in it we may re- 

 cognise two layers, the internal of which is rich in vessels ; and an epithelium, 

 or membrana granulosa, consisting of round or polygonal granular cells. 

 At the bottom of the ovisac, this epithelium forms a small mass the cumulus 

 proligerus (or germinal eminence), in the centre of which is the ovulum or 

 egg of the mammal. The contents (liquor folliculi) are a clear yellow fluid, 

 which becomes red on admixture with blood when the vesicle ruptures. 



The ovulum or ovum is a cell about l-100th of an inch in diameter, 

 inclosed in the discus proligerus or cumulus proligerus. The ovulum is 

 invested by an amorphous, thick cell-membrane the zona pellucida (mem- 

 brana vitellina) ; its granular contents are named the vitellus or yelk ; and 

 its (vesicular nucleated) nucleus, designated the germinal vesicle, and lying 

 at a certain point on the zona pellucida, has in its centre a white patch the 

 germinal spot. 



Vessels and nerves. The thick, flexuous, arterial divisions are given off 

 by the utero-ovarian artery ; they ramify in the spaces formed by the tunica 

 albuginea, before reaching the proper tissue by entering the hilus. The 



