DEVELOPMENT OF THE WOLFFIAN BODIES, ETC. 789 



that which is inside the same point, is developed into the uterus. The 

 upper portion of the cord itself becomes the ligament of the ovary ; its 

 lower portion, the round ligament of the uterus. 



As the ovaries continue their descent, they pass below and behind the 

 Fallopian tubes, which perform at the same time a movement of rota- 

 tion, from before backward and from above downward ; the whole, 

 together with the ligaments of the ovaries and the round ligaments, 

 being enveloped in double folds of peritoneum, which enlarge with the 

 growth of the parts included between them, and constitute finally the 

 broad ligaments of the uterus. 



While these changes are taking place in the adjacent organs, the two 

 lateral halves of the uterus fuse with each other upon the median line, 

 and become covered with an abundant layer of muscular fibres. In the 

 quadrupeds, the uterus remains divided at its upper portion, running 

 out into two long conical tubes or cornua (Fig. 228), presenting the 

 form known as the uterus bicornis. In the human species, the fusion 

 of the two lateral halves of the organ is nearly complete ; so that the 

 uterus presents externally a somewhat rounded, flattened and triangular 

 figure (Fig. 229), with the ligaments of the ovary and the round liga- 

 ments passing off from its superior angles. Internally, the cavity of 

 the organ still presents a strongly marked triangular form, the vestige 

 of its original division. 



Occasionally the human uterus in the adult condition remains divided 

 by a vertical septum, running from the middle of its fundus downward 

 toward the os internum. The organ may even present a partial external 

 division, corresponding with the situation of the internal septum, and 

 producing the malformation known as " uterus bicornis," or double 

 uterus. 



The os internum and the os externum are produced by partial constric- 

 tions of the original generative passage ; and the anatomical distinctions 

 between the body of the uterus, the cervix, and the vagina, arise from 

 the different modes of development of the mucous membrane and mus- 

 cular tunic in its corresponding portions. During foetal life, the neck 

 of the uterus grows faster than its body; so that, at the period of birth, 

 the organ is far from presenting the form which it exhibits in the adult 

 condition. In the human foetus at term, the cervix uteri constitutes 

 nearly two-thirds of the entire length of the organ ; while the body 

 forms but little over one-third. The cervix, at this time, is larger in 

 diameter than the body; so that the 'whole organ presents a tapering 

 form from below upward. The arbor vitae uterina of the cervix is at 

 birth very fully developed, and the mucous membrane of the body is 

 also thrown into three or four folds which radiate upward from the os 

 internum. The cavity of the cervix is filled with transparent semi-solid 

 mucus. 



The position of the uterus at birth is different from that which it 

 assumes in adult life; nearly the entire length of the organ being above 

 the level of the symphysis pubis, and its inferior extremity passing 



