270 BOVINE OBSTETRICS 



Oehrnke constructed a short saw which is very practical 



(fig. 61). 



The chisel (fig. 62) is used in subcutaneous embryotomy 

 to separate the branches of the inferior maxilla, the thorax, 

 the sacro-iliac articulation, a curved neck and symphysis 

 pubis. To use it, the obstetrician's hand carries it to the part 

 to be cut, while an assistant drives it with light blows from a 

 wooden mallet through the bones. 



Fig. 61.— Finger Saw. 



Instead of the chisel, the sharp heart-shaped spatula may 

 be employed to split the ischio pubic symphysis. It is intro- 

 duced by covering it with the hand, and is placed against the 

 symphysis. A light blow with the other hand against the free 

 portion drives it into the cartilage. By further twisting and 

 pushing it, the symphysis is separated. Forceps serve to 



tfJHft 



Fig. 62. — Embryotomy Chisel. 



extract portions of the foetus after the skin has been separated; 

 for instance, the branches of the jaw, the neck, the thoracic 

 wall, the dorsal and lumbar region, the sacrum and one half of 

 the pelvis. They may be dispensed with when we accustom 

 ourselves to use the sharp probe-pointed hook and the rope. 

 Kruijt, Andre and Van der Linden have constructed useful 

 forceps for embryotomy. 



3.— Partial Embryotomy. 



Indications. — Partial embryotomy confines itself to remov- 

 ing certain parts of the calf, to render possible the passage 

 of the balance of the body. It is indicated when certain foetal 

 diameters exceed the pelvic dimensions. When the bioostal 



