Normal Parturition 519 



tuberosity of the ischium passes upward toward the sacrum and 

 causes a decrease in the tension of the great sacro-sciatic 

 ligaments. 



Another symptom of approaching birth, which is important, is 

 the preparation which is taking place in the vulva. The vulvar 

 lips become somewhat thickened and tend to stand apart more 

 loosely than ordinarily. From the vulva there generally appears, 

 especially in the cow, a more or less abundant discharge of a 

 thick, ropy mucus, which indicates an increase in the functional 

 activity of the glands in the mucosa of the vagina and vulva. 

 If the lips of the vulva are parted, there is observed an injection 

 of the mucosa. 



As the time for birth draws nearer, certain psychic signs are 

 observed, which indicate that the period of labor is rapidly ap- 

 proaching. The animal seems to be somewhat disturbed and 

 anxious. It tends to move slowly and cautiously and exhibits 

 some tendency to isolate itself from its usual associates. There 

 may be interruptions in feeding, suggesting that uterine contrac- 

 tions are taking place, which cause some degree of discomfort 

 or pain. These may express themselves through an appearance 

 of anxiety on the part of the animal. Sometimes the advent of 

 the uterine contractions is suggested by the appearance of slight 

 colic, accompanied by occasional pawing or lying down, or, in 

 case of carnivora, whining or groaning. The mare may show 

 evidence of pain by whisking the tail, a symptom which is seen 

 to some extent also in the cow. Finally the pregnant animal, if 

 at liberty, tends to withdraw from other animals of its own kind 

 or of other species and seek a quiet and secluded place, where it 

 may bring forth its young without disturbance or annoyance. 



In herbivora, little care is taken in the selection of a place for 

 giving birth to young, except that it is a quiet spot where the 

 mother and young may for & time remain more or less in hiding. 

 The carnivorous animal shows a tendency to select a comfortable 

 bed. 



The sow, in a state of freedom, will habitually gather coarse 

 herbage or small brush into a conical mound, in which she may 

 give birth to her young. If allowed the fullest liberty, at a 

 season of the year when vegetation is abundant, she will select a 

 spot where she can gather an abundance of coarse weeds or fine 

 twigs which are covered with leaves. Beginning at the spot 



