242 NORMAL PARTURITION. 



the inlet, and is preceded, accompanied, or followed by the head and 

 fore limi)S : the situation and direction of which may vary without 

 altering the essential features of the presentation. 



2. Posterior Presentation. — The croup or breech is facing the inlet, 

 and the presence or absence of the limbs there only constitutes a variety 

 of the presentation. 



3. Dorso-lwnbar Presentation . — Any portion of the upper part of the 

 body opposite the inlet. Lecoq and Eainard admit presentations of 

 the withers, back, loins, shoulder or haunch, as distinct presentations ; 

 but I agree with Saint-Cyr in declaring the distinction to be practically 

 useless. On exploring the pelvic cavity, no matter what part of the 

 back is first touched, the hand always encounters the spine of the 

 foetus, either directly in the axis of the pelvis, or obliquely and at some 

 distance from it. All these varieties may, therefore, be reduced to the 

 one now named, and which may be either direct or oblique, according 

 as the case may be. 



4. Sterno-abdominal Presentation. — The limbs in this case are in reality 

 first touched, and we may have all four, or only three or two ; these, 

 however, are not the fixed point of the presentation, which is the 

 inferior part of the body — or sterno-abdominal region — hence the 

 designation. 



These four principal presentations have been divided into natural or 

 normal, in which spontaneous or unaided birth is possible ; and into 

 connatural or abnormal, in which parturition is impossible without 

 human intervention. The longitudinal presentations alone comprise 

 the first, although they are not always normal ; as a wrong direction of 

 the head or limbs may prove an obstacle more or less difficult to 

 overcome, and requires the aid of art. In the anterior presentation. 

 the head passes before the body, but in the posterior presentation it 

 follows the body ; in the former presentation the extended fore limbs 

 accompany the head, as there is space for them, for the diameter of the 

 chest being really greater than that of the pelvic inlet, there would not 

 be room for them to pass through if they were alongside the thorax. 

 In the 2)osterior j^resoitation also the hind limbs should be extended, as- 

 if flexed they would add to the volume of the trunk. In the Carnivora 

 the head is generally larger than the chest, so it does not matter so 

 much if the fore legs are thrown back. Taking this view into considera- 

 tion, the presentations may either he simple, or more or less comj)! icated , 

 according to circumstances. 



SECTION II.— POSITIONS. 



The presentation being determined by the part of the foetus which 

 offers at the pelvic inlet, it must be evident that this part, whichever it 

 chance to be, may vary considerably in its relations to the circum- 

 ference of that passage. If the chest of the foetus first enters it, the 

 attitude of this region may be very different in different cases ;, 

 in one the withers may correspond to the sacrum of the mother, and 

 the sternum to the pubis, or the reverse msij happen ; in another the 

 foetus may be lying on the right side, the sternum corresponding to^ 

 the right branch of the mother's ilium, and the withers to the left 

 ilium, or vice versa. So that here are four different positions in the 

 same presentation — the anterior; and it will readily be understood 

 that it should be the same, or nearly the same, for the other presenta- 

 tions. 



