"If the superior strait does not constantly present the same figure in deformed pelvis; if it is sometimes larger on one side than the other; if one of the acetabula is nearer to the sacrum, while the other approaches less; if the symphysis of the pubes is removed in many cases from a line which would divide the body into two equal parts, it is because the rickets has not equally affected all the bones of the pelvis, nor equally hurt all their junctions; and because the attitude which the child takes in walking or sitting may change a little the direction of the compressing power, which I have just mentioned." (_Baudelocque_, translated by Heath, vol. i. p. 60.) Nor is it necessary that the degree with which the disease affects the different parts of the pelvis should vary in order to produce these inequalities of distortion, for there is no reason to suppose that the promontory of the sacrum would approach the symphysis pubis in a straight line, even where the softening of the bones was uniform throughout; the attitude of the child, as above-mentioned, and the manner in which it supports itself, will have no inconsiderable influence in determining the direction in which the distortion takes place. In those instances where the promontory is forced low down into the pelvic cavity, the sacrum becomes bent upon itself, the upper part of it forming a sharp curve backwards, while its lower portion together with the coccyx being confined by their attachments, and more or less compressed by sitting, are directed forwards. This is not seen where the projection of the promontory is but slight; the curve of the sacrum so far from being increased is rather lessened; the sacrum is straighter and flatter than usual, so that, although the brim of the pelvis is contracted, we not unfrequently find the outlet even larger than natural: in other cases, where the softening of the bones has gone to a considerable extent, the outlet is diminished, from the tubera ischii having been forced inwards.