DIAGNOSIS AND CORRECTION OF MALPOSITIONS 229 



Although the instrument can be used occasionally to ad- 

 vantage, it is better to replace it by the hand. Retropulsion 

 of the calf is aided materially by placing the hindquarters of 

 the cow into an elevated position, or, if possible, inducing the 

 cow to stand up. When the feet are braced well, the hand, 

 resting upon the forehead or nose of the calf, can exert just as 

 much force as the goblet-repeller. Giinther had an instrument 



* 



Fig. 29.— Repeller. 



made for the same purpose, termed by him " obstetrical 

 crutch." It consists of an iron cylinder 75 cm. long, having on 

 the one end a concave cross-piece and a handle on the other. 

 It is used by placing it against the cervical portion of the 

 sternum and the calf repelled ; while doing so the hand must 

 always accompany the instrument. The calf may also be re- 

 pelled by Gunther's crutch when in the posterior presentation ; 

 that is, the buttock toward the pelvic inlet ; in such a case it is 

 placed against the postero-external angles of the ischium. 



Trager's Wire Loop. 



An instrument of similar construction is that crutch es- 

 pecially used for retropulsion in the posterior presentation 

 (fig. 29). The rod of this instrument has a concave transverse 

 piece with a spike ; the latter is introduced into the arms. 



Trager had a wire loop made of brass, mainly to fix the 

 head when flexed backward. The above cut (fig. 30) gives an 

 idea of the instrument. In order to secure displaced parts, 

 which cannot be reached with the cord, so-called porte-cords 

 have been constructed. Gunther's porte-cord (fig. 31) consists 

 of two iron rods placed upon each other, 78 cm. long. The 

 upper one is provided with a handle and ring, so that the- 



