PRESENTATION OF THE PELVIS. 321 



§. I. Presentation of the Feet. 



538 out of 37,895, Madame Lachapelle ; 23 in 1800, Merriman; 18 in 1897, 

 Bland; 68 in 6555, Boer. 



776. What I have stated in relation to the dangers of delivery by 

 the pelvic extremity, applies strictly to presentations of the feet. In 

 that case the child resembles a cone or a very sharp wedge, descend- 

 ing from its point towards its base; the bag of waters being generally 

 less regular in shape, more elongated than in other positions, and al- 

 most always rupturing before the dilatation of the neck has had tim6^. 

 to be completed, it follows that the pressure upon the foetus constant' 

 ly increases from the root of the lower limbs up to the superior part 

 of the chest, and that the viscera are violently repelled from beloviT 

 upwards; in one word, the parts of the woman are dilated, and a pas- 

 sage for the head opened by the hips, the belly, and the thorax. If 

 the abdominal and thoracic cavities were formed of bones as solid, 

 and if their horizontal diameters were of length equal to those of the 

 head, they would bear the pressure of the os uteri with quite as little 

 inconvenience, and the child would not run much more risk in one 

 way than in the other; but this is not the case, and I cannot too 

 strongly insist upon the disadvantages of such presentations. 



1 . Calcaneo-Anterior Position. 



347 in 37,895 cases, Madame Lachapelle. 



• ■ A. First Variety. 



Loins in front and towards the left. 



1st position of Baudelocque, Gardien, Maygrier, Capuron, Madame Boivin and 

 M. Desormeaux. 



777. In the first position of the feet, the anterior surface of the 

 foetus looks backwards and to the right of the womb; the right hip is 

 turned towards the left sacro- iliac symphysis, and the left hip towards 

 the right acetabulum; whence it follows, that if the presence of the 

 rectum were the principal cause of the great proportional frequency 

 of the first vertex position, the first position of the feet ought to be 

 more rarely met with than the second; however, the contrary is ob- 

 served to happen; for, by the statement of Madame Boivin, in a total 

 of 234 labors by the feet, the left calcaneo-acetabular position alone 

 occurred 135 times. 



778. The heels, which previously to the rupture of the mem- 

 branes are more or less near to the tuberosities of the ischia, do not 

 actually engage within the os uteri, until the moment v/hen the 



