424 DYSTOCIA. 



any other position, it is very natural that when pressed by the organ 

 in which it is enclosed, it should gradually, and without much diffi- 

 culty, reassume the situation it occupies when in its natural circum- 

 stances. When the womb contracts, if the foetal ovoid is well situ- 

 ated, it becomes compressed equally in every direction, but if, on 

 the contrary, it is in a deviated position, its extremities support 

 almost alone, the whole effort of the contraction, and but for the 

 shoulder, which is from its salient form apt to be arrested at the 

 strait, either the head or the breech would be almost always brought 

 to the strait. 



For this consequence to fail taking place, which is almost impos- 

 sible, the middle of the child's body ought to correspond exactly Jo 

 the centre of the pelvis, so that, of its two extremities, one should not 

 be more disposed than the other to slide up towards the fundus, or 

 down to the orifice of the womb; besides, the difference of the shape 

 of the head and breech would render tliis equilibrium extremely 

 difficult. There is nothing very extraordinary, therefore, in the evo- 

 lution or spontaneous version of the child; it is quite a natural phe- 

 nomenon, easily explained by the action of the womb and its rela- 

 tions to the form of the ovum and fcetus. The mechanism of this 

 evolution explains why the anterior and posterior positions of the 

 trunk are so rare, and shoulder cases so common. If, when some 

 point on the dorsal or abdominal surface of the child offers at the 

 strait, the head of the pelvis are too far removed from it to be 

 brought back again, the pains never fail to act with a certain degree 

 of force upon the two extremities of the bis-acrimonial diameter, 

 which then becomes inclined, and one of the shoulders is soon com- 

 pelled to engage in the open part of the strait. 



963. To conclude, from the above details I think it follows: 



1st. That all those positions of the trunk that cannot be referred 

 to those of the shoulder, the back, or the anterior part of the thorax, 

 ought to be classed among the inclined positions of the head. 2d. 

 That shoulder presentations are, so to speak, the only ones that re- 

 quire particular attention, inasmuch as all others are naturally reduced 

 to them. 3d. That the child is never situated completely crosswise 

 in the womb, and that the most untoward positions may sometimes 

 be expected to be reduced to those that are most favorable. 4th. 

 That there are a good many cases, in which the interference of art 

 is any thing but indispensable, although the fcetus may present by 

 neither end of its great diameter. 



964. The indications to be fulfilled in cases of faulty position of 

 the child necessarily vary according to a great variety of circum- 

 stances. Until the waters are discharged, nothing is to be done. 



