DYSTOKIA BY DISPLACEMENT. 



289 



in covering it like a carpet, to line the upper surface of the pubic bones 

 and the pelvic cavity. 



From this anatomical peculiarity, it may happen that the fundus of the 

 gravid uterus, instead of being directed forward, will incline directly 

 downwards and lie on this pelvic step, not passing beyond the umbilicus, 

 behind which it may even rest sometimes. At the same time, and as a 

 consequence of this arrangement, the other end — the cervix — is tilted 

 upwards in the direction of the sacro-vertebral angle, and it may even 

 compress the rectum against that part. It will be obvious that, through 

 this great deviation in the direction of the cervix, the os no longer cor- 

 responds to the axis of the vagina, the canal following, of course, the 

 same oblique ascending line as the cervix. Such an alteration in the 

 position of the uterus entails a similar change in the attitude of the 

 foetus, which, instead of being placed almost horizontally, is now more 

 or less vertical — the head towards the sacrum, and the buttocks resting 

 on the pubic step. 



During parturition, as Saint-Cyr points out, we may easily understand 

 how affairs are changed with regard to the performance of this act. The 

 uterine contractions are no longer directed towards the cervix ; the os 

 only dilates slowly or not at all, according to the degree of uterine ob- 

 liquity ; the animal is exhausted with ineffectual attempts to expel the 

 foetus ; and if assistance is not rendered, it may succumb without being 

 delivered, or the uterus may rupture. Garreau has observed that labor 

 may be suspended altogether- ; the foetus dies, becomes mummified, and 

 is retained for perhaps a very long time. 



Diagnosis. 



The diagnosis of this deviation does not appear to be attended with 

 much difficulty. The long duration of labor, and the inutility of the 

 expulsive efforts, prove that some obstacle to delivery must be present. 

 Consequently, vaginal exploration is resorted to, and when the hand is 

 passed into that canal it reaches a kind of imperforate cul-de-sac, at the 

 bottom of which is a large round tumor into which no opening can be 

 found. This tumor is the lower face of the uterus which, pressed against 

 the corresponding wall of the vagina, projects into the pelvic inlet. 

 Raising the hand towards the sacrum, the os will be discovered much 

 removed from its normal position, and situated above in front of the 

 uterine tumor just alluded to. 



Sometimes the os is completely closed, in other cases it may be more 

 or less dilated. When in the latter condition, there is frequently formed 

 at this point a kind of membraneous transverse fold, raised in the form 

 of a valve which has been compared to a fleshy band analogous to 

 that which forms the sacculations of the large intestine ; this band is 

 stretched across the lower part of the os, and it has to be surmounted 

 before the hand can touch the foetus. The latter is lodged in a kind of 

 pouch or excavation situated beneath the band, and constitutes the tu- 

 mor met with at first at the bottom of the vagina. 



Complicatio7is. 



To Saint-Cyr, Garreau, and Schaack, we are indebted for our descrip- 

 tion of the condition we have been describing, and to the two latter are 

 also due the knowledge we possess of certain complications which are 

 worthy of notice. 19 



