DISEASES OP THE GENERATIVE ORGANS. 171 



in anticipation of the severe strain put upon them as the solid body 

 of the calf passes. 



The cow often calves standing, in which case the navel string is 

 broken as the calf falls to the ground. If, however, she is recumbent, 

 this cord is torn through as she rises up. The afterpains come on 

 three or four hours later and expel the membranes, which should 

 never be left longer than twenty-four hours. 



NATURAL PRESENTATION. 



When there is but one calf the natural presentation is that of the 

 fore feet with the front of the hoofs and knees turned upward toward 

 the tail of the dam and the nose lying between the knees. (PI. XV. ) 

 If there are twins the natural position of the second is that of the hind 

 feet, the heels and hocks turned upward toward the cow's tail. (PL 

 XVIII, fig. 1. ) In both of these natural positions the curvature of the 

 body of the calf —the back arched upward — is the same with the curva- 

 ture of the passages, which descend anteriorly into the womb, ascend 

 over the brim of the pelvis, and descend again toward the external 

 opening (vulva). Any presentation differing from the above is 

 abnormal. 



OBSTACLES TO PARTURITION. 



With a well-formed cow and calf and a natural presentation as above, 

 calving is usually prompt and easy. Obstacles may, however, come 

 from failure of the mouth of the womb to dilate; from twisting of 

 the neck of tlje womb; from tumors in the vagina; from dropsy in 

 the womb or abdomen; from over distension of the rectum or bladder; 

 from undue narrowing of the passages; from excess of fat in the walls 

 of the pelvis; from the disturbance of a nervous cow by noises; from 

 stone or urine in the bladder; from wrong presentation of the calf, 

 its back being turned downward or to one side in place of upward 

 toward the spine of the dam; from the bending backward into the 

 body of the womb of one or more limbs or of the head ; from presen- 

 tation of the back, shoulder, or croup, all four limbs being turned 

 back; from presentation of all four feet at once; from obstruction 

 caused by an extra head or extra limbs, or double body on the part of 

 the offspring (PI. XIX) ; from dropsy or other disease of the calf; from 

 excessive or imperfect development of the calf; from the impaction 

 of twins at the same time into the passages; or it may be at times 

 from the mere excessive volume of the fetus. 



GENERAL MAXIMS FOR THE ASSISTANT CONCERNING DIFFICULT PAR- 

 TURITION. 



Do not interfere too soon. "Meddlesome midwifery is bad" with 

 animals as with women. After labor pains set in, give a reasonable 

 time for the water bags to protrude and burst spontaneously, and only 



