In all cases where the irregularity in form, or diminution in size, is such as to prevent the passage of the child an operation becomes necessary, either upon the mother or her infant, and great danger is consequently incurred by both.

It is therefore the duty of every mother, if she has the slightest suspicion that her daughter is deformed, though it may not be apparent, to have her examined before she is allowed to marry. Many have lost their lives for want of this precaution. Severe blows or falls in early life may also create a pelvic deformity, and this, as a possible consequence of such accidents, should always be borne in mind. The means by which the form and size of the pelvis are ascertained, as before stated, are simple, and such as need not in any way be feared.

To enumerate all the varieties of deformed pelvis, as described by different authors, is unnecessary, and would not be useful here. I shall therefore only refer to them generally. Sometimes the pelvis is regular enough in its form, but singularly small altogether, not larger perhaps than that of a child eight or nine years of age. More frequently, however one part only is small, while the others are full sized, or the different parts are not in a proper position in regard to each other. Thus sometimes the pubic bones will be flattened backward, near to the sacrum, so as to narrow the antero posterior diameter of the upper strait; at other times one of the sides will be flattened towards the other, as if crushed in, and thus diminish all the diameters; and at other times one side will sink down lower than the other, and thus effect similar changes in another way.

By referring to the description of the perfect pelvis, given in the early part of the work, the nature of these changes will be readily understood, particularly if the plates given there are compared with those given here.

PLATE XL.

Represents the standard form, with which the rest must be compared.

PLATE XLI.

Represents a pelvis which resembles that of the male in its form, and is therefore called masculine. It is deeper, and less capacious altogether than the standard one. This form is occasionally met with in females of a peculiar general conformation, and temperament, approaching that of the other sex. It is not a sufficient deviation from the natural form to create any great difficulty, though it may cause delay.