Interlocking of the Fetal and Maternal Pelves 773 



3. Upward Dbviation of the Head. 



The upward deviation of the head is exceedingly rare in prac- 

 tice, and is due to some accidental misdirection while the fetus 

 is passing along the birth canal. In most animals, and especially 

 in the foal, a primary upward deviation is so un.stable that the 

 head is very liable to drop off to one side and, revolving some- 

 what upon its long axis, assume a more or less lateral displace- 

 ment. Owing to the anatomical peculiarities of the head and 

 neck, this displacement is perhaps most frequently observed in 

 carnivora, where it may constitute a very serious obstruction to 

 birth. 



The diagnosis is not readily made in the smaller domestic ani- 

 mals. In the larger ones, where manipulation is practicable, the 

 obstetrist finds upon the insertion of his hand that, though the 

 position is dorso-sacral, the head is not readily grasped or touched, 

 and that the trachea of the fetus, freely exposed and presenting 

 toward the pelvic inlet, emerges from the chest and turns upward 

 and then backward to disappear along the sacrum of the mother. 



The indications are analogous to those already related under 

 lateral deviation. First we should consider the question of re- 

 pulsion and correction of the deviation by methods already de- 

 scribed. Second, before exhausting the strength of the opera- 

 tor or of the patient, if the replacement is difficult, or threatens 

 to be futile, embryotomy is to be recommended, and should be 

 carried out upon the same basis as in the lateral deviation. 



Caesarian section, page 663, necessarily constitutes ^ valu- 

 able and available method for handling this deviation in the 

 carnivora, where the hand of the operator cannot be inserted 

 along the genital passages to correct the vicious position. As in 

 other cases of hysterotomy, the operation should here be under- 

 taken early, before the patient has become exhausted or the 

 fetuses have perished and become emphysematous, and especially 

 before the genital passages have been lacerated and infected in a 

 vain effort to bring about extraction by other means. 



d. Dystokia in the Anterior Presentation, 

 Due to the Hips. 



Interlocking of the Maternal and Fetal Pelves. 



It not infrequently occurs, especially in the cow, that birth 

 ias proceeded with more or less facility, with the fetus in an ap- 



