THE FEMALE ORGANS OF GENERATION. 



591 



consolidated with the body of the uterus, and enveloped in its thick 

 layer of muscular fibres. 



The mucous membrane of the body of the uterus in its usual condi- 

 tion is smooth, of a rosy color, and closely adherent to the subjacent 

 muscular tissue. It consists of tubular follicles, ranged side by side, 

 and opening on its free surface. Their secretion is probably destined 

 for the nutrition of the embryo during the early periods of its formation. 



The cavity of the body of the uterus terminates below by a con- 

 stricted portion, termed the os internum, by which it is separated from 



FIG. 165. 



GENERATIVE ORGANS OF THE HUMAN FEMALE. a, a. Ovaries. 6, 6. Fallopian tubes, c. Body of the 

 uterus, d. Cervix, e. Vagina. 



the cervix. The inner surface of the cervix is raised in prominent 

 ridges, arranged usually in two sets, diverging on each side from a 

 central longitudinal ridge ; presenting the appearance known as the 

 "arbor vitae uterina." The follicles of this part of the uterine mucous 

 membrane are of a sac-like form, and secrete a tenacious mucus, which 

 serves during gestation, to block up the cavity of the cervix, and thus 

 prevent the escape or injury of the egg. 



The cervix uteri presents inferiorly a second constriction, the " os 

 externum ;" and below this comes the vagina, constituting the last divi- 

 sion of the female generative passages. 



The accessory female organs of generation consist, therefore, of ducts, 

 through which the egg is transported from within outward, varying in 

 development, in different animals, according to the functions which they 

 perform. In the lower orders, they serve mainly to convey the egg 

 to the exterior, and to surround it more or less abundantly with albu- 

 minous secretions; while in the mammalia and in man, they are adapted 

 to the more important office of retaining the egg during gestation and 

 providing a vascular supply for the nourishment of the embryo. 



