908 OF GENERATION ACTION OF THE FEMALE. 



attached ; and the blood in moving through them produces a peculiar mur- 

 mur, which is usually distinctly audible at an early period of pregnancy, 

 and may be regarded (when due care is taken to avoid sources of fallacy), 

 as one of its most unequivocal positive signs. The "placental bruit" is thus 

 described by Dr. Montgomery: 1 "The characters of this phenomenon are, a 

 low murmuring or somewhat cooing sound, resembling that made by blow- 

 ing gently over the lip of a wide-mouthed vial, and accompanied by a slight 

 rushing noise, but without any sensation of impulse. The sound is, in its 

 return, exactly synchronous with the pulse of the mother at the time of ex- 

 amination ; and varies in the frequency of .its repetitions, with any accidental 

 variation which may occur in the maternal circulation. Its situation does 

 not vary during the course of the same pregnancy ; but in whatever region 

 of the uterus it is first heard, it will in future be found, if recognized at all, 

 for it is liable to intermissions, at least, we shall occasionally be unable to 

 hear it where we have already heard it a short time before, and where we 

 shall shortly again recognize it. According to my experience, it will be* 

 most frequently heard about the situation of the Fallopian tube of the right 

 side ; but it may be detected in any of the lateral or anterior parts of the 

 uterus." That the cause of this sound exists in the Uterus itself, is distinctly 

 proved by the fact, that it has been heard when that organ was so completely 

 onteverled, that the fundus hung down between the patient's thighs. A sound 

 so much resembling this as to be scarcely distinguishable from it, may be oc- 

 casioned, however, by a cause of a very different nature, namely, an abdom- 

 inal tumor, pressing upon the aorta, iliac arteries, or enlarged vessels of its 

 own ; and, in doubtful cases, it is necessary to give full weight to the possi- 

 bility of such an explanation. The sound may be imitated at any time, by 

 pressing the stethoscope on the iliac arteries. The placental bruit has been 

 not unfrequently heard in the eleventh week ; but it cannot generally be 

 detected before the fourth mouth, when the fuudus uteri rises above the an- 

 terior wall of the pelvis. 



758. The increase in the size of the Uterus, which takes place pari pa**u 

 with the enlargement of the ovum, is accompanied with a remarkable aug- 

 mentation in the amount of its substance. Up to about the fifth or sixth 

 month, not only its cavity, but the thickness of its walls is progressively 

 added to; from that time to the end of gestation, the thickness of the walls 

 diminishes whilst the cavity increases, but not in an equal proportion ; and 

 at the conclusion of parturition, its solid bulk is estimated at about twenty- 

 four times that of the uuimpregnated Uterus. The augmented volume of 

 the organ is chiefly due to the increased development of its Muscular coat, 

 which is composed of the fusiform cells with staff-shaped nuclei, that make 

 up the " non-striated " muscular fibre elsewhere. According to Prof. Knlliker, 

 a vast amount of ne\v fibres are generated during the early months of preg- 

 nancy ; but there is at the same time an extraordinary increase in the size of 

 those previously formed, their length being multiplied from seven to eleven 

 times, and their width from twice to five times. After the sixth month the 

 origination of new muscular fibres seems'to cease, but the augmentation in 

 the size of those already generated seems to continue. The connective tissue 

 which unites the muscular fibres also increases during pregnancy, and be- 

 comes more distinctly fibrous. 2 It has been shown by Dr. Lee;' in his beau- 

 tiful preparations and drawings, that the Nerves of the Uterus, which are 



s of Proo;nanc i y. p. 121. 

 " Sec Kiillikcr's Manuul (Syd. Soc. Ed.), vol. ii, pp. 258, 259. 

 3 Phil. Transact. 1811, 1842, 1840, 1849. 



