THE OVARIES 597 
and a half (ca. 3-4 em.) thick. The weight is about two and a half to three 
ounces (ca. 70-80 grams). 
Each presents for description two surfaces, two borders, and two extremities. 
The surfaces are termed medial and lateral (Facies medialis, lateralis); they are 
both smooth and rounded.t The attached or mesovarial border (Margo mes- 
ovaricus) is convex. It is enclosed in a part of the broad ligament termed the mes- 
ovarium; the vessels and nerves reach the gland at this border. The free border 
(Margo liber) is marked by a notch which leads into a narrow depression, the 
ovulation fossa. The tubal or anterior extremity (Extremitas tubaria) is rounded, 
and is related to the fimbriated end of the uterine 
tube. The uterine or posterior extremity (Extremitas 
uterina) is also round, and is connected with the horn 
of the uterus by the ovarian ligament. 
The ovaries are situated in the sublumbar region, 
and are usually ventral to the fourth or fifth lumbar 
vertebra. They are usually in contact with the lum- 
bar wall of theabdomen. The average distance from 
the ovaries to the vulvar orifice is about twenty to 
twenty-two inches (ca. 50-55 cm.) in a mare of 
medium size. 
The position of the ovaries is very inconstant, as might 
be expected from their mode of attachment. Either ovary or 
both may be deflected transversely in either direction to the 
full limit allowed by the mesovarium. The so-called medial 
and lateral surfaces are usually dorsal and ventral, or vice 
versa, according to the direction of the deflection. The range 
of variation in the longitudinal direction is greater than was 
formerly thought to be the case. The right ovary is often 
about six inches (ca. 15 em.) behind the corresponding kid- 
ney, but the distance between them may be nearly twice as 
great or may be only about two inches (ca. 5 cm.). The left 
ovary is usually a little (ca. 2-3 cm.) further back than the right 
one, but is usually nearer the corresponding kidney, the average 
distance between them being about four inches (ca. 10 em.). 
They may be about two inches (ca. 5 em.) from the extremity 
of the corresponding cornu of the uterus or in contact with it. 
Except during pregnancy, they are almost always in contact 
with the lumbar abdominal wall, and do not hang down among 
the adjacent viscera. Fic. 531—Ricur Ovary oF Mare, 
WITH ADJACENT STRUCTURES. 
The ovary is attached to the sublumbar region The extremity of the cornu is 
by the anterior part of the broad ligament of the °Pened: 7, Ovary; 1% corpus luteum; 
5 5 a 2, uterine or Fallopian tube, with its 
uterus; this part of the ligament, the mesovarium, ostium abdominale (2’), fimbrie (2”), 
is about three or four inches'(ca. 8 to 10 cm.) wide, 4nd ostium uterinum (2’”); 3, cornu 
measured from the ovary directly to the parietal at-  “°" "iB is mucous Tining (3) ex- 
posed; 4, ligament of ovary; 4’, meso- 
tachment. The uterine extremity of the ovary is  salpinx. (After Ellenberger, in Leiser- 
connected with the extremity of the cornu of the 22's Atlas, reduced.) 
uterus by the ligament of the ovary (Lig. ovarii pro- 
prium); this is a band of unstriped muscle enclosed between the layers of the broad 
ligament. 
Structure.—The greater part of the surface of the ovary has a covering of 
peritoneum. The peritoneal investment is absent at the attached border where 
the vessels and nerves enter; this area is termed the hilus of the ovary (Hilus 
ovarii), although there is no depression here. The ovulation fossa is covered by 
a layer of short polygonal cells, a remnant of the primitive germinal epithelium. 
1 These terms apply properly only when the adjacent viscera are removed and the ovaries 
are actually “suspended”? by the broad ligaments. When the ovary is in its natural position, 
the surfaces are usually dorsal and ventral, the former corresponding to the “‘lateral’’ surface if the 
free border is directed outward, to the “medial’’ if the free edge is medial. 
