OF THE GENITAL FUNCTION OF WOMAN. 345 



cular layer of fibres which covers the upper segment of the 

 gravid uterus. The fibres arise from the round ligaments, and 

 regularly diverging, spread over the fundus until they unite and 

 form the outermost stratum of the muscular substance of the 

 uterus." 



" The substance of the gravid uterus is powerfully and dis- 

 tinctly muscular ; but the course of the fibres is here less easily 

 described than might be imagined. Towards the fundus the 

 circular fibres prevail ; towards the orifice the longitudinal fibres 

 are most apparent ; and, on the whole, the most general course 

 of the fibres is from the fundus towards the orifice. This preva- 

 lence of longitudinal fibres is undoubtedly a provision for dimi- 

 nishing the length of the uterus, and for drawing the fundus 

 towards the orifice. At the same time these longitudinal fibres 

 must dilate the orifice, and draw the lower part of the womb 

 over the head of the child. 



In making sections of the uterus while it retained its natural 

 muscular contraction, I have been much struck in observing how 

 entirely the blood vessels were closed and invisible, and how 

 open and distinct the mouths of the cut blood vessels became 

 when the same portions of the substance of the Titerus were dis- 

 tended and relaxed." " A very principal effect of the muscular 

 action of the womb is the constringing of the numerous vessels 

 which supply the placenta, and which must be ruptured when the 

 placenta is separated from the womb." 



" Upon inverting the uterus and brushing off the decidua, the 

 muscular structure is very distinctly seen. The inner surface of 

 the fundus consists of two sets of fibres, running in concentric 

 circles round the orifices of the Fallopian tubes. These circles at 

 their circumference unite and mingle, making an intricate tissue. 

 Ruysch, I am inclined to believe, saw the circular fibres of one 

 side only,* and not adverting to the circumstance of the Fallo- 

 pian tubes opening in the centre of these fibres, Avhich would 



* Discovered by Weitbrccht, and first accurately observed by Dr. Hunter. 



