If there be but one foot, it is not enough to recognize it as such, but we must know if it is the right or the left foot. The best plan is, to determine all its characteristics: its great toe, its internal border, and the heel; then to mentally substitute one's own foot for the one felt, in such a manner that, as Tarnier and Chautreuil express it, " the heel, the internal border, and the toes can be, as it were, superimposed over each other." This will show whether the right or left foot has been touched.
The presentation of the knees is so rare that it is hardly necessary to speak of the diagnosis. They form a round prominence, limited be hind by the popliteal space, and adjoining the thigh on one side and the leg on another.
The diagnosis of the positions is easy when the presentation is known.
When the breech presents, the direction in which the coccyx points, always toward the anterior plane of the foetus, indicates which side is oc cupied by the back. When the breech presents together with the feet, the latter are crossed, and applied, the right to the left buttock, the left to the right buttock, the soles directed backward, the toes of the left foot pointing to the right lateral plane, those of the right foot to the left lateral plane; the heels face in the opposite direction, the right heel to the right, the left to the left side, both turned toward the posterior plane of the foetus. Hence, if the toes of the right foot point backward and to
the left, the back is in front and to the right; inversely, if they point backward and to the right, the back is in front and to the left; if they point forward and to the right, the back is behind and to the left; if they point forward and to the left, the back is behind and to the right. The diagnosis can be reached in like manner from the left foot; here, too, it is best, as in the presentation, to substitute mentally one's own foot for that of the foetus, and ascribe to it the same attitude; thus it will be seen that, in order to obtain it, one's back will have to be brought to the right or left, in front or behind, as the case may be.
Finally, if the feet alone present, the direction of the heels indicates the side where the back is, and thereby the position.
Budin has recently called attention to a fact which we have also had occasion to verify several times; namely, that the pelvic extremity is not always as elevated as is generally stated, and that it is not very rare to see it so deeply engaged as to be taken for the vertex, on superficial exam ination.