506 OBSTETRICAL OPERATIONS. 



fear ; next, being formed of small and flexible cords, which are well 

 oiled before use, it cannot injm-e the maternal organs in any way ; 

 thirdly, from the manner in which it acts on the neck, the lower jaw, 

 and the face, and the impossibility of its becoming tighter when once 

 it is fixed, it is absolutely inoffensive, so far as the foetus is concerned ; 

 and, finally, owing to the nose-loop, it always keeps the head in a good 

 direction, prevents it from deviating, and compels it to follow the 

 course most favourable for its extraction : in the words of Schaack him- 

 self, " Without exaggeration, the forceps of the accoucheurs could not 

 answer better for the human foetus." As an agent of prehension and 

 traction — but particularly the latter, Saint-Cyr asserts that he does not 

 know of anything superior to this apparatus. 



Shaack's halter is more especially applicable to the Bovine foetus, 

 the head of which is so much larger and squarer than that of Solipeds, 



Fig. 163. Fig. 164. 



Haltek with a Single Traction Halter with Two Traction 



Cord. Cokds. 



a. Check-knot ; h, Running Knot or a, b, Two ends of the Cord ; r, 



Loop. Check-knot on the a portion ; d, Run- 



ning Knot or Loop on the b portion. 



and sometimes requires very energetic pulling to remove it from the 

 pelvis. 



It is not always an easy task, however, to place anything like a 

 formed halter over the head, especially if this is in the genital canal ; so 

 that it has been found more convenient to make the halter on the 

 head. Detroye^ takes a cord about ten feet long, in the middle of 

 which he makes a simple knot — a check-knot ; this is passed by the 

 hand or porte-cord around the neck behind the head, and the knot 

 withdrawn to the vulva ; a loop or running-knot is made on the cord 

 at a certain distance from the check-knot, and the shorter portion of 

 the cord is passed through it, the loop being tightened and run up 

 until it is close to the knot (Fig. 164). The length of cord between the 

 two knots should be sufficient to encircle the upper part of the neck, 

 and form a kind of halter without the nose portion ; the loop may be 

 made previously, when it is possible to make it glide on the head, 



^ Recueil de Medecine Vetdrinalre, 1889, p. 309. 



