278 ANIMAL PHYSIOLOGY. 



surrounding a granular yelk; and, in the interior of this, 

 to one side, is a clear nucleus called the germinal vesicle, 

 with a distinct nucleolus, the germinal spot. The ova are 

 developed within organs called ovaries, which are placed one 

 on each side in the lower part of the abdomen, and are flat- 

 tened oval bodies, about an inch and a half long, invested 

 with peritoneum. Each is attached by a fibrous cord to the 

 upper part of the uterus. 



Pig. 141.- UTERUS AND OVARIES from the front, a, Vagina with 

 os uteri depending into it ; 6, cavity of cervix uteri, with 

 rugose mucous membrane ; c, cavity of f undus uteri, exposed in 

 the right half ; d, round ligament of uterus ; e, e, Fallopian tubes, 

 the right one laid open; /, /, ovaries; g, round ligament of ovary; 

 h, parovarium, 



203. The uterus or womb is a muscular organ placed, in 

 ordinary circumstances, within the pelvis. It is a pear-shaped 

 body about three inches long, flattened from before back- 

 wards, and connected with the abdominal wall in each groin 

 by means of a round ligament. When clipped open it is seen 

 to have exceedingly strong walls; its lower portion, the 

 cervix, extending for about an inch upwards from the mouth 

 or inferior opening (os externum), surrounds a separate cavity 

 with rugose mucous membrane, divided by a constriction 

 (os internum) from the smoothly-lined main cavity, destined 

 for the reception and development of the ovum. This main 

 cavity, contained within the body or f undus of the uterus, 

 although destined to undergo enormous temporary enlarge- 

 ment in pregnancy, is of small size at other times, with its 



