PROCESS OF EVOLUTION OF THE UTERUS 7 



surfaces of the mucous membrane adhere, thus preventing 

 fecundation. 



Therapeutics demands the removal of the mucus and the 

 opening of the os uteri with the finger or dilator. Sterility 

 may also be caused by occlusion of the ovarian extremity of 

 the Fallopian tube (Harms), absence of os uteri, uterus 

 (Hekmeijer), or chronic endometritis. 



2. — The Process of Evolution of tlie Uterus. 



As soon as conception takes place the uterus undergoes 

 numerous changes, enabling it to fulfil its task, primarily 

 noticeable in the mucous membrane. Hypersemia, which sets 

 in during oestrum, continues, also increased secretion and 

 desquamation. The greater amount of blood causes increased 

 metabolism, increased nutrition and hypertrophy of the organ, 

 increasing in ratio with the dimensions of the embryo, which 

 is known as foetus at the moment circulation within it is 

 completed. In single pregnancy, the fecundated horn, if twins, 

 both cornua usually increase in size. 



As pregnancy advances the uterus increases in size and 

 changes its position. In the latter stages it lies in the right 

 inferior abdominal region, as the rumen extends from the left 

 flank to the right lower lateral region. The uterus is related 

 on the left to the rumen, on the right it rests against the 

 abdominal parietes. The anterior free end, not supported by 

 the broad ligaments, is covered by the great omentum. The 

 broad ligaments simply enclose the non-pregnant uterus. 

 They continue to carry blood vessels to the uterus, which 

 often become greatly enlarged ; the lumen of the uterine 

 artery, for instance, increases four to five times, the smaller 

 vessels become quite large and the network of lymph vessels 

 expands. The broad ligaments become broader and longer, 

 numerous muscular fibres form and unite into broad, muscular 

 bands. Increase of size of the uterus is accompanied by a 

 very slight decrease in the thickness of its wall, which is 

 entirely out of proportion to the increase in size ; thus, hyper- 



