It is desirable also to hold the examining finger of the right hand against the frænulum perinei when a pain comes on, because then we know exactly when the tension of the perineum is becoming such as to endanger its integrity, and when the head is about to pass out. Until this moment the frænulum is seldom on the stretch, although the rest of the perineum is: hence we need not apply our support until now, and thus give the parts the full benefit of the dilating force, which the head exerts upon them, until the very last instant. To relax them still farther, the patient's knees ought not to be separated by a pillow or cushion placed between them, as is usually done, although it must be confessed that in some cases she is relieved by it. In applying the left hand to support the perineum, it should be placed somewhat more backward than the spot which we intend to support: for by this means we are enabled to push the soft parts somewhat forwards, and thus relax them. By this means, also, we not only direct the head against the other parts of the os externum but avoid the danger of its perforating the perineum. When the moment of greatest distension arrives, the process cannot be too slow; we must therefore desire the patient not to bear down, and endeavour, if possible, to make the head remain in the state of _crowning_ until the next pain comes on: the os externum having been held for some moments at its utmost dilatation, permits the head to pass with greater ease and safety. As the globe of the head passes forwards and emerges through the os externum, we feel the posterior portions of the perineum become soft and lax, while the forehead, followed by the face, and lastly the chin glide over the anterior margin of it.