OF TRUE PREGNANCY. Ill 



natural state, larger and less tortuous, they enlarge, and are developed 

 still more rapidly than the arteries; at term they are observed to 

 furrow the fleshy layer in every direction, and form a net-vi^ork which 

 in some measure separates it into two planes. They are large 

 enough to admit a goose quill, and in some instances, even the end 

 of the little finger; near the mucous membrane they dilate so as to 

 constitute cones with inverted bases; cones described by Astruc, 

 under the name of uterine sinuses, but which Haller restored to 

 their proper nature by denominating them venous sinuses; and to 

 which Hunter thinks no particular name should be given. 



281. The lymphatic vessels are, according to Cruikshank, so 

 amplified that they may, by injecting them with mercury, be made as 

 large as crow-quills, and to form a kind of coating of silver to the sur- 

 face of the womb; the nerves themselves, according to Hunter, also 

 increase sensibly in size; which accounts for certain alterations of 

 function we shall have occasion to treat of in a subsequent page. 



282. The mucous membrane, the existence of which it is so dif- 

 ficult to demonstrate in the unimpregnated state, becomes more 

 evident, redder, more villous; distinct shreds of it can be separated; 

 the folds which it forms for the purpose of enclosing the ridges of 

 the cervix, relax and disappear, but not until the last half of preg- 

 nancy; the serous coat also is far from being unaffected by all these 

 changes, and Bichat was evidently mistaken when he asserted that 

 the peritoneum, like the other diaphanous membranes, possesses 

 no extensibility. At the end of pregnancy, the meso-rectum re- 

 mains; the broad ligaments, and other folds, though tightened, are 

 not effaced, yet lose some of their proportional dimensions, and even 

 somewhat of their absolute dimensions. Besides, admitting that 

 they do become completely unfolded, their laminae would be insuffi- 

 cient to cover a circumference of twenty-six inches. It is evident, 

 then, that the serous coat increases in the same proportion as the 

 fleshy coat of the womb; that it is extensible, and remains in con- 

 tact with the same points of the subjacent layers, from the com- 

 mencement to the end of gestation. I have even remarked, as M. 

 Ristelhueber has, that, instead of becoming thinner, it rather increases 

 in thickness, and that its adherences scarcely relax at all while it is 

 undergoing this amplification. 



283. Functions and properties. In proportion as the uterine 

 vessels deploy themselves, the blood is determined thither, and at 

 last the womb, like a sponge, is gorged with that fluid; however, 

 the menses are suppressed as soon as fecundation is effected, and 

 some physiologists have attributed to this circumstance most of the 

 modifications which are then experienced by the womb; but we 



