224 INTRA-PEL VIC A MPU TA TION. 



neum of the fetus is reached and make a free incision 

 through that region involving the anus in the male fetus 

 and the anus and vulva in the female and enlarge the 

 incision sufficiently to admit the operator's hand into the 

 fetal pelvis. lyocate the great sciatic ligament and insert- 

 ing the knife at the shaft of the ilium divide the former 

 backward to the perineum, thus enlarging the pelvic 

 cavity and giving ample operating room. If the pelvis of the 

 fetus is too small to admit the hand of the operator at all 

 before severing the sciatic ligament, this may be accom- 

 plished by cautiously cutting from behind forward with 

 Colin's scalpel or with the chisel. When this has been 

 severed and sufficient operating room attained carry the 

 chisel with one hand and place it against the shaft of the 

 ilium as shown between I' I' in Plate XXXVIII as nearly 

 perpendicular to the long axis of the iliac shaft as possible 

 and keeping the hand in touch with the chisel blade, have 

 an assistant drive it through the bone until it and its peri- 

 osteum are completely severed. Disengage the chisel and 

 then place it against the symphysis pubis or against the 

 ischium opposite the foramen ovale and drive it through the 

 ischium and pubis at this point, Using the chisel as a 

 lever, separate the isolated portion of the pelvis as com- 

 pletely as practicable from the surrounding tissues, and with 

 the fingers separate the muscles from the detached pelvic 

 bone for a short distance from the severed ends on either 

 side. Carry a cord in, pass the loop over the ends of the 

 severed section and tightening it secure the isolated portion 

 of the pelvis and have one or more assistants exert traction 

 as indicated in Plate XXXIX. The chief obstacle to the 

 withdrawal of the limb is the great gluteus muscle which 

 should be sought for, identified and torn through with the 

 fingers at a distance of 5 or 6 cm. from its attachment to the 

 great trochanter. Other important points of resistance are 

 the attachment posteriorly of the skin, vulva and anus to 



