Embryotomy 647 



and the limb. The process may be aided by incision with a knife 

 or with the chisel. 



When the foregoing are well divided, the remaining impedi- 

 ments to tearing the shoulder away consist essentially of the 

 trapezius and rhomboideus muscles at the top, the latissimus 

 dorsi behind, and the great serratus and angularis scapula, all of 

 which come into action only whetj the shoulder is nearly severed, 

 and then offer no serious resistance. Consequently it is only 

 necessary to separate the skin from the limb and divide the pecto- 

 ral muscles in order to readily draw the limb away by traction. 



When the skin has been detached and the pectoral muscles di- 

 vided, two or three assistants exert traction upon the limb, while 

 the operator places his hand against the sternum and pushes in 

 the opposite direction. The impact upon the maternal organs 

 from the traction may be reduced to any desired degree, by ap- 

 plying a repelling force to the sternum of the fetus. 



The impact upon the maternal organs equals the difference be- 

 tween the traction applied upon the cord and the repulsion applied 

 to the fetal sternum. Should the hand of the operator not 

 suffice, the repeller should be applied, carefully guarded by the 

 hand of the operator, the necessary force being supplied by one 

 or more assistants. 



Should the traction fail to bring the limb away promptly, the 

 operator should attempt to extend the division of the muscles 

 attaching the limb to the thorax, while moderate traction upon 

 the limb is continued. 



Further diminution of the size of the fetus may now be had by 

 the removal of the other limb in the same way. This is especially 

 desirable in the transverse presentation with all four limbs in 

 the passage. The size of the trunk may also be further reduced 

 by evisceration, as described on page 658. 



When a foal presents anteriorly in the dorso-sacral position, 

 with lateral deviation of the head which it is impracticable to 

 correct, the subcutaneous removal of one anterior limb, followed 

 by evisceration, so reduces the volume of the fetus that the rem- 

 nant can be easily withdrawn without correcting the deviation 

 of the head. It also renders the fetal remnant so flaccid, and 

 so far increases the room by the reduction of size, that the devia- 

 tion is easily corrected. 



