increase circulation in tin' sinuses. since tliis is essential for changing piw-.ure 

 upon tin- l)l<HHl, while the va^t numlier of muscles and nerves in tln> walls of the 

 womb are the provision for more energetic action than is possible to the 

 placenta, which is composed almost entirely of vascular loops. 



'2. The womli .-.ii IT* HI in/* -the emliryo. and its a<-tion would therefore be more 

 etl'ective for producing the changes in pressure upon it, which is also in imilnlii /. 

 <(' ir/nit t'iki'x /ilni-i in /In- uiitiiinn of the grow ing chick, it beJBgZOOked to mid 

 fro in the egg b\ the slow rhythmical expansions and contractions taking place 

 iu the amnion i|i. -I'.I'.M. and by alternating this ai-tion with the one taking place 

 in the placenta, it is readilv jH'rceived how a rapid circulation could be main 

 tained in the maternal and placental sinuses for compelling correspondence 

 lietwecn this and the energetic circulation in the emliryo, since it all forms a 

 connected whole. This would also be in conformity with the principle 

 in the circulation, the blood flowing from high to low pressure. As 

 the placenta i-.i-fiiimlx for reducing pressure within itself, and for increasing 

 pressure in the emlir\o. *///, <//////. ..W// and /iri JMWXH with this action the entire 

 muscular walls of the womb <;<ntr<i<t for increasing pressure in the maternal 

 sinuses for eomi>elliiig this blood in the placenta, at the same time by increasing 

 pressure upon the embryo it should determine a more rapid movement 

 from the latter to the placenta ; the one involving the other. But when the 

 placenta contracts for increasing pressure (thereby compelling the blood out 

 of itself in two directions, or toward the embryo and the maternal sinuses), 

 the uterine walls expand for reducing pressure in the embryo and the uterine 

 Minist s, thus greatly expediting the placental efflux; and, taking it all in all, 

 there can lie very little doubt but that the force which is represented in the 

 muHled murmur of the placental souffle is mainly the product of the muscular 

 uterine walls, though l>oth undoubtedly contribute to it. 



'.'<. This action in the uterus and placenta would account for the very curious 

 and suggestive n/i/ii/n//// in that portion of the canals connecting the uterine 

 with the placental sinuses, being upon a line almost paraUeJ with the transverse 

 axis of the uterus and placenta, which is precisely what is called for by the 

 special mechanics, in order to effect the lateral or to-ond-fro movements, the 

 vessels simply elongating and contracting with these, as the case may be, with- 

 out interfering with the calibre of the tubes. Were the vessels straight, it 

 would be utterly impossible to operate this mechanics, since the lateral move- 

 ments should obliterate the vessels by closing the calibre. It could not be 

 otherwise, in the very nature of things. In the accompanying diagrams (Figs. 

 3, 4), the vessels are represented as nearly perpendicular, but this is done 

 simply for better definition. 



I. lint the strongest proof, perhaps, of this higher function of the womb is 

 furnished in the \asmlar and nervous connections subsisting lietween it and 

 the maternal organism. And as all this relates to circulation for building up 

 and elaborating the embryo, obviously the mechanics for increasing circulation 

 in the womb commensurate with that in the embryo should extend to the vessels 

 of supply or the feeders, as also the discharging vessels, or the arteries and 

 \eins. It must be shown how this new movement, this new life set going 



