658 Proceedings of the Royal Society 
counter-pressure, or pressure against a fixed wall, and that chiefly 
during the temporary abeyance of the power of parturition. There 
is to be noted, also, in connection with this curve, the inevitable 
tendency of the force of labour, not merely to distend the perineum, 
hut also to rupture it centrally, to force the presenting part through 
it ; a tendency the study of which, apart from other considerations, 
leaves no possible doubt as to the expediency of the practice of 
supporting the perineum, a practice which can he demonstrated to 
favour the maintenance of its entirety. 
A novel practice, founded upon what I regard as a misapprehen- 
sion of the conditions of this curvature, has been recently much 
dwelt upon by Professor Schultze of Jena.* The practice has for 
its object to facilitate and promote the advance of the child after 
its head has reached the floor of the pelvis. It is proposed to effect 
this by extension of the spine, with a view to which a hard pillow 
is to be placed beneath the loins as the woman lies on her back. 
The extension of the spine he believes to increase the posterior 
obliquity of the axis of the uterus, and therefore of the force of 
labour as exerted in this part. By the change supposed to be thus 
effected in the direction of the axis of the uterus, the axis of the 
force of labour is brought more nearly to the direction of the axis 
of the outlet of the pelvis, whereby there is supposed to be pro- 
duced a diminution of the otherwise necessary loss of power arising 
from the change of direction of the passage at this part. Schultze 
alleges that he has found this extension of the spine to be useful 
in practice. If this utility is confirmed and ascertained, nothing, 
of course, can be said against it. But for the enforcement of his 
recommendation of this practice, it is evident that he trusts chiefly 
to theoretical arguments; and, therefore, I proceed to examine 
them, and believe I shall show that they are fallacious. Before 
doing so, it is worth while to point out that the attitude recom- 
mended by Schultze is a very unnatural one, and that a woman 
straining in labour advanced to the stage at present under conside- 
ration naturally assumes an attitude nearly opposite to that implied 
by extension of the spine, an attitude of some degree of flexion, 
an attitude which, keeping in view the relaxed state of the sacro- 
* See Jenaische ZeitsGhrift fiir Medicin, &c. Band iii., 1867, and Lehrbuch 
fur der Hebammenkunst, 1870. 
