of Edinburgh, Session 1871 - 72 . 
651 
tory is made too general. It can be true and applicable only where 
the posterior uterine obliquity is present, and it is not demonstrated, 
nor is it probable that this always is so, in cases of deformity. 
It is extremely desirable that means should be devised for ascer¬ 
taining the direction of the resultant of the combined forces of 
parturition, and especially of the axis of the uterus in action. 
The means adopted by Schatz with this object in view are not 
satisfactory; they merely go the length of showing how carefully 
he entered upon the question. But it may be permitted me to 
state reasons which tend to establish the ordinary opinion, and to 
discountenance that of Schatz. 
If the uterine axis is inclined to the brim of the pelvis poste¬ 
riorly to its axis, we should expect to find the child’s head at the 
commencement of labour, while yet above the brim, to be in a posi¬ 
tion which has never, so far as I know, been ascribed to it in 
natural cases. Smellie, in his plate xii., gives this position con¬ 
sistently, but not truly. He could not avoid doing so, unless he 
represented the child at rest as having a left lateral flexion of the 
head, which would be ridiculous. His mode of drawing the uterus 
with this posterior obliquity created an exigency for him, which he 
could get over only by what must be regarded as misplacement of 
the head. One error thus led him into another. The erroneous 
posterior uterine obliquity forced him to represent the left side as 
presenting in the very commencement of labour in an ordinary 
case of first cranial position with the occiput looking to the left. 
I do not see how the difficulty, Smellie’s yielding to which gave 
rise to error, can be avoided, except by assuming that the ordinary 
view as to the axis of the pregnant uterus is correct. 
At the same point where Smellie stumbled, Nsegele also fell into 
error, but in an opposite direction. In his classical essay on the 
mechanism of birth, describing the first position of the foetal head, 
he represents it as presenting at the brim of the pelvis, which it 
has not yet fully entered, more obliquely than when it has entered 
it, or as having at the earliest stage its perpendicular axis more 
inclined anteriorly to the axis of the brim; and in this way he 
accounts for his allegation that the right ear can generally be felt 
at this time without difficulty behind the pubic bone.* Here a 
* See the work of H. F. Nsegele, “ Die Lehre voro Meckanismus der 
Geburt.” Mainz, 1838, S. 12. 
