232 BOVINE OBSTETRICS 



merit 5.4 cm. wide. These hooks, closing in the same way as a 

 forceps, do not injure the uterine walls. It is Vogel's opinion 

 that they can be used to draw forward limbs retained in the 

 uterus, to extract a fully developed dead foetus, to remove in- 

 accessible parts after embryotomy, etc. 



The plain hook of Vogel is provided with a hinge and 

 spring in the curved portion of the hook, so that the point 

 of the hook can be held in the hand (fig. 36). 



A very useful instrument is Obermayer's hook, its segment 

 having a width of 4.5 cm. (fig. 37). 



ss&s 



Fig. 38.— Kaiser's Double Borer. 



Kaiser constructed a double auger to adjust misdirected 

 parts of a dead foetus (fig. 38). The double end, shaped like a 

 corkscrew, is bored into the skin or parts below and can be 

 retracted into the canula. 



2.— Classification of Abnormal Presentations. 



The longitudinal presentation was previously termed a 

 normal presentation, and represents a position in which the 

 long axis of the foetus runs parallel with the long axis of the 

 mother. It must be at the same time an abdominal position — 

 that is, the abdomen of the calf lies opposite to the belly of the 

 mother. In this position the head, resting upon the fore legs, 

 as well as the hind legs, may enter the parturient passage. We 

 look upon both as normal. In either case the conditions for 

 the passage of the foetus are very favorable, and parturition 

 usually takes place without assistance. Any deviation from 

 that position interferes with expulsion, as the dimensions of 

 the calf do not correspond with those of the pelvis of the row. 



The obstetrician then attempts to correct the presentation, 

 in order to aid the passage of the calf through the pelvic 

 canal. 



