In the first pregnancy the passage of gas through the intestines may be mistaken for quickening long before the movements of the child are really perceptible; but those who have once experienced quickening will not be deceived. Whenever women who have borne children are in doubt the sensation is almost surely not quickening. Furthermore, in any doubtful case, the motion should be observed by a physician before being accounted a positive sign of pregnancy. This precaution will scarcely delay an absolutely positive diagnosis, since the proper method of examination reveals these movements to the physician almost as early as the patient feels them. About the time these movements become perceptible another positive sign is available. The physician whose ear has been trained to catch such sounds when he listens over the lower part of the mother's abdomen will hear the fetal heart-beat. Other sounds may be audible there, but the character and the rate of the heart-sounds are distinctive. Since the child's heart beats almost twice as fast as the mother's, under ordinary conditions it is impossible to confuse one with the other. The mother never feels the beating of the child's heart, but occasionally she will mistake for it the throbbing of her own blood vessels. Ability to hear the fetal heart not only provides a means of confirming the existence of pregnancy in doubtful cases, but also enables the physician to reassure his patient if she fails temporarily to feel the child move. Sometimes the presence of twins is recognized in this way. Toward the end of pregnancy the heart sounds are also of material assistance in determining what position the child has permanently assumed. There is a third positive sign of pregnancy to which the physician has recourse, but generally it is inapplicable as early as those already mentioned. In the latter months of pregnancy it is possible to outline the child through the mother's abdominal wall. Although this procedure adds little or nothing to our resources for making an early diagnosis, the information it ultimately affords proves one of the greatest aids in the practice of obstetrics.