The _mons Veneris_ is a rounded eminence composed of fatty tissue, which surmounts the pubic bones and is covered with hair at puberty. From it two prominent longitudinal folds of skin, covered with hair on the outside, the _labia majora_, extend backward, forming the lateral boundaries of the vulva. Within these labia again are two thin cutaneous folds, the _labia minora_ or _nymphæ_, which run back from the clitoris for about one and a half inches and enclose the _vaginal orifice_. The _clitoris_ corresponds to the penis and is just above the upper part of the labia minora. Between it and the vagina is the _meatus urinarius_. The orifice of the vagina is partly closed in the virgin by the _hymen_, a thin fold of mucous membrane, which occasionally closes it completely, _imperforate hymen_. The _fourchette_ is a small transverse fold of skin at the junction of the labia minora posteriorly. Between the vagina and the rectum is the _perineal body_, a somewhat triangular structure made up of many small muscles. Its surface is known as the _perineum_. It is frequently torn wholly or in part during childbirth and has to be sewed up. CHAPTER XII. THE UPPER EXTREMITIES. The upper extremities include the shoulders, arms, forearms, wrists, and hands and contain each thirty-two bones. The bones of the two shoulders taken together are called the _shoulder girdle_ and consist of the two clavicles or collar bones and the two scapulæ or shoulder blades, which together make an almost complete girdle of the shoulders. The =clavicle= is a long slender bone extending almost horizontally from the sternum to the scapula and can be felt for its whole length in the living. For the inner two-thirds it is convex anteriorly, for the outer third concave. In woman it is generally less curved, smoother, and more slender than in man, and as bone is rough when the muscles attached are powerful, the right clavicle, being used more, is generally rougher and thicker than the left. Among the muscles attached are the large neck muscle, the _sterno-cleido-mastoid_, whose tendons form the _presternal notch_, the _trapezius_, the _pectoralis major_, and the _deltoid_. Being slender and superficial the clavicle is most frequently _broken_ of any bone in the body, generally by indirect violence, as by falling with the hand out, though old people in such a case are apt to get _Colles’ fracture_ at the wrist. The bone generally gives way at the juncture of the outer and middle thirds, with displacement of the parts inward, so that the fracture is seldom compound. Since, however, the main vessels of the upper arm, with their nerves, lie beneath the clavicle, there is danger of their being punctured. Such serious injury is guarded against by the presence of the _subclavius muscle_. The clavicle is occasionally removed for _sarcoma_. [Illustration: FIG. 68.--Bones of the upper extremity. (Toldt.)] [Illustration: FIG. 69.--Left scapula, posterior surface (after Toldt).]