Ef?ibryotomy . 651 



ward beyond its fellow, and the remnant of the severed ilium I' can 

 drop inward or move in any direction. The entire pelvis thus 

 loses its rigidity and undergoes diminution in size, so that it can 

 readily be withdrawn. 



B. Embryotomy in the Posterior PrEvSEntation. 



a. Amputation of the Posterior Limbs at the Tarsus. 

 When a fetus, especially a foal, presents posteriorl^^ with one 

 or both posterior limbs retained at the tarsus, it may be difficult 

 or impossible to repel the fetus and extend the feet. The diffi- 

 culty of the correction of such a deviation is intensified by re- 

 cumbency, the comparatively large size of the fetus, and by fetal 

 emphj'sema. In such cases it is frequently easier for the ob- 

 stetrist and safer for the mother to amputate the limb or limbs 

 at the tarsus. 



Technic. Pass a cord around the leg above the tarsus, as indi- 

 cated in Fig. no, and have an assistant hold the leg steady by 

 gentle traction. Introduce the chisel, carefully guarded in the 

 palm of the hand, and place it against the lower part of the tar- 

 sus, as shown between T and T. The chisel should be placed 

 as nearly perpendicular to the long axis of the metatarsus as pos- 

 sible. The proper direction of the chisel may at times be greatly 

 favored by placing the cord upon the metatarsus instead of the 

 tibia, thus forcing the tarsus toward the sacrum of the mother 

 and tending to throw the metatarsus straight across the pelvic 

 cavity. 



The chisel should at all times be held in the palm of the hand, 

 with the dorsal surface of the hand against the vaginal or uterine 

 walls, and the instrument carefully guarded and guided during 

 the entire operation. The amputation should preferably be 

 through the lower section of the tarsus, but may be made through 

 the head of the metatarsus. The chisel should not be ^driven 

 entirely through the hock without removal, as it may oecome 

 caught and clamped between the divided bones; instead, drive it 

 first for only a few inches along the lateral side of the tarsus, being 

 sure that the skin at that point is included in the cut along with 

 the bone. Then loosen the chisel, and force the divided bones 

 apart by rotating the instrument upon its long axis, after which 

 it may be driven somewhat deeper into the tarsus, until the foot 

 is completely severed. 



