56 BOVINE OBSTETRICS 



Many experienced stock owners know how to correct this 

 abnormality, by fixing the calf and placing the cow in a dorsal 

 position, when but litte traction delivers the calf. The knowl- 

 edge of pelvimetry explains to us what these people empiric- 

 ally but successfully executed. 



By giving the calf a quarter turn, the trochanteric dia- 

 meter of the calf is rendered parallel to the vertical diameter 

 of the inlet ; in other words, the greatest diameter of the hind 

 quarters of the calf pass through the greatest diameter of the 

 pelvic inlet. 



The knowledge of pelvimetry explains many theoretical 

 and practical data, and while the latter is not immediately 

 perceived, its practical value cannot be denied. Many a little 

 trick applied by the experienced obstetrician, and which in 

 certain cases is of great use, is not thought of by the beginner. 

 The practice of this vocation demands great circumspection 

 on the part of the veterinarian and is surrounded by peculiar 

 difficulties ; for this reason nothing should be omitted which 

 would enhance his theoretical, and especially practical, know- 

 ledge. 



2. — The Soft Parts of the Genital Passage. 



In describing the process of evolution, the changes in 

 the texture and position of the uterus were discussed. The 

 canal which the foetus must follow during expulsion, commonly 

 termed genital passage, at the time of birth differs so much 

 fron that of the uuimpregnated state, as to demand a detailed 

 discourse. 



The walls of the pelvic canal, the form and dimension of 

 which have just been described, surround mainly the rectum, 

 urinary bladder and vagina. When the rectum is empty — as 

 is the rule during parturition — it having been emptied by 

 repeated defsecation in the preparatory period, its walls col- 

 lapse, leaving but a limited space between them. Besides 

 that, the concavity of the inferior face of the sacrum is suffi- 

 ciently deep to receive the rectal walls without materially 

 decreasing the vertical pelvic dimensions. 



