218 THE FCETUS. 



upon insertion of the placenta over the cervix, may come from the 

 vessels of the placenta, and consequently, from the foetus, as well as 

 from the mother. When blood flows from the uterine end of the 

 cord that has just been cut, it is not at all because the circulation 

 continues to go on from the womb to the placenta, but it is simply 

 owing to the contraction of the womb and of the vessels of the 

 placenta itself, and of the cord; it is the after-birth disgorging the 

 fluids it contained, and not new blood coming from the woman. The 

 presence in the foetal organs of medicinal or alimentary substances 

 taken by the mother, is explained by the laws of imbibition or by 

 absorption, quite as satisfactorily, as by an uninterrupted continuity 

 of the vascular systems of the ovum and uterus. 



560. Still there are the anatomical injections: they have been in 

 vain attempted by Ruysch, Haller, &;c., but as a thousand negative 

 facts do not destroy a single positive one, these injections are con- 

 stantly appealed to in support of the hypotheses in question. 



561. M. Dubois formerly exhibited to the Academy of Surgery, 

 a specimen he had prepared, and in which the injection passed into 

 the placenta, through what he denominated the placento-uterine 

 vessels; Chaussier succeeded in impelling Mercury into it; Beclard 

 and M. Duges have succeeded with colored oil. In the body of 

 of a pregnant woman prepared for examination, M. Deneux saw the 

 uterine sinuses completely filled with injection, and continuing 

 without any line of demarcation into the placental sinuses, which 

 were also filled with the same material. Mr. D. Williams has re- 

 cently performed some experiments, from which it appears that 

 linseed oil, injected into the aorta or hypogastric arteries, penetrates 

 into the organs of the foetus; and M. Biancini, who has performed 

 experiments on one woman who died whilst in labor, on another 

 Avho died in a week after delivery, and on a third who died with 

 flooding, as also on cats, rabbits and cabiais, assures us he obtained 

 the same results with size and with mercury, which he thinks, 

 answer better than oil; in addition to the utero-placental arteries, 

 the Italian physiologist describes a set of veins of a corresponding 

 character. 



562. But it seems to me there is a strange misconception of the 

 value of such experiments. How happens it that they have not 

 been regarded as but little applicable to the explanation of what 

 takes place in the living female? How long has the passage of 

 foreign matters from one vessel to another proved incontestably 

 that the same thing takes place with the natural fluids during the 

 life of the individual? 



563. When a pretty fine injection is thrown into the arteries of 



