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Proceedings of the Royal Society 
ing power; but it is evident that this can only be the case if a 
variety of conditions be satisfied. Of these the following are pro¬ 
bably principal:—the assistant driving force, which is auxiliary to 
the proper uterine force, must be also directed in the axis of the 
brim of the pelvis, being supposed to be uniformly applied to the 
uterus by the circumjacent viscera and parts, acting like a fluid, 
exerting pressure equally in all directions: the uterus must be dis¬ 
tended with a fluid which is copious enough to prevent any part of 
the walls being specially pressed upon or indented by the foetus; 
or, it must have its tendency to become spheroidal superiorly unre¬ 
strained. Now Schatz, in addition to giving the proper uterine 
driving force a posterior inclination to the axis of the brim by 
ascribing to the uterine axis such an inclination, still further in¬ 
creases the inclination of the whole driving force, by describing 
the special direction of the auxiliary bearing-down driving force as 
still more inclined than the direction of the uterine axis. The 
resultant of the combined or whole driving forces will of course, 
according to Schatz, have a direction somewhere intermediate be¬ 
tween that of the uterine and that of the auxiliary driving forces. 
Smellie’s authority is much relied upon in support of the exist¬ 
ence of this curve. In his plates he gives the uterus this inclination 
to the axis of the brim of the pelvis, both in natural cases and in cases 
of deformity ; but this is not satisfactory evidence as to what he 
believed, for it is probable that in preparing his plates he did not 
pay particular attention to the point. Those of them to which 
reference is here made (as xii. and xiv.) are not in the proper 
sense drawings or pictures, but mere plans, and might very well 
have been arranged as they are, merely because in other respects 
the works looked well. Dr Barnes, in his recent work on obstetric 
operations, while adhering to the generally entertained view as to 
the coincidence of the axis of the uterus and of the brim of the 
pelvis, implies, by his descriptions and drawings, a belief that, in 
most if not all cases of antero-posterior contraction of the brim of 
the pelvis, the uterine axis is inclined to the axis of the contracted 
brim, as Schatz believes it to be in cases generally. This is not the 
place for any full criticism of what Barnes very aptly calls the curve of 
the false promontory, because I confine myself to ordinary or natural 
conditions. I shall merely say that this important and practically 
valuable doctrine of Barnes regarding the curve of the false promon- 
