228 NORMAL PARTURITION. 



touched, the hand always encounters the spine of the foetus, either di- 

 rectly 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. 



Sterno-abdo7mnal PresentaHo?t. — The limbs in this 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 may be divided into natural ox nor- 

 mal, in which spontaneous or unaided birth is possible ; and into rmnat- 

 ural ox abnormal., in which parturition is impossible without the interven- 

 tion of man. The longitudinal presentations alone comprise the first, 

 although they are not always tiortnal : as a wrong direction of the head 

 or limbs may prove an obstacle more or less difficult to overcome, and 

 may require the aid of art. So that, taking this view into consideration, 

 the presentations may either be simple, or more or less complicated, accord- 

 ing 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 

 may be, may vary considerably in its relations to the circumference of 

 that passage. If, says Saint-Cyr, 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 may happen ; in another the foetus may be lying 

 on the right side, the sternum n:orresponding to the right branch of the 

 mother's ilium, and the withers to the left ilium, or vice versd. 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 presentations. 



The position has accordingly been defined to be the relation of a de- 

 terminate point on the surface of the foetus, to an equally determinate 

 point of the pelvic circumference. The points, so far as the mother is 

 concerned, may be determined once for all, and they will always remain 

 the same for every presentation ; they may be, for instance, the sacral 

 region above, the pubic below, and the two ascending branches of the 

 ilium at the sides. If, with the foetus, we select any region — say the 

 withers — and put this part in relation with any of th^se four points of 

 the pelvic circumference, we shall have four successive and easily recog- 

 nized positions. If, therefore, we first give the name of the region in 

 the foetus, and next that of the pelvic circumference with which it 

 is in relation, we have a ready means of designating the positions : 

 describing the foetus to be in a vertebrosacral position, for instance, when 

 its vertebral region is in relation with the sacrum of the mother. The 

 fixed points may be invariable in the latter ; but they cannot be so with 

 the foetus, as they will vary with each presentation. 



With regard to the anterior and posterior presentations, Rainard has 

 selected the fixed points as follows : for the first, he has taken the spi- 

 nous processes of the dorsal vertebrEe in the region of the withers ; for 

 the second, the lumbar vertebrae. For the positions in the other two pre- 

 sentations, he has not been so fortunate in a designation, in the opinion 



