Pelvic Co7istriction 



677 



and movable sacro-iliac articulation on the other side, whenever 

 traction was applied, the pubis moved toward the sacrum and the 

 channel closed like a cam. The fetus was dead and the mare 

 was worthless, so that delivery by other means was ignored and 

 the animal was at once destroyed. 



d. Exostosis, as a result of dislocation of the femur 

 through the foramen ovale. Fig. 1 13A illustrates the pelvis 

 of a cow, in our collection, in which there has been an old stand- 

 ing dislocation of the femur through the foramen ovale. As a 

 result of the constant irritation there has developed a large ex- 

 ostosis inside the pelvis, which would naturally cause serious 

 obstruction in case of parturition. Exostoses or bone tumors 

 may arise in the pelvic canal from various causes, and offer more 

 or less serious obstruction to birth. 



e. Eminences along the ischio-pubic symphysis, Fig. 

 113 B, are not rare in the pehis of the mare. Their cause is 



Fig. 113B. Pelvis of Mare. 



Showing prominent elevations. A, B and C on the anteriormargin of 



the pelvic inlet. 



