=Lightening.=—In the last two weeks, especially in primiparæ, the child’s head sinks into the pelvis, and its body falls a little forward. The uterus sinks down and forward with the child. The waist-line lowers, the stomach region is flatter, the navel more prominent. The patient breathes easier, but does not walk as well. =Duration of Pregnancy.=—Average time is 280 days; protracted, 314; a short term about 245 days. There is no positive period. =Prediction of the Date of Labor.=—Count 9 calendar months from the beginning of the last menstruation and add 7 days. An error of 2 or 3 weeks, however, is possible. (See Table on page 178.) =Premonitory Symptoms of Labor.=—(1) _Lightening._—Dropping may be attended with slight pains similar to labor pains. (2) _False Pains._—These vary in nature and quality. They may be short and sharp, or long and continuous, or irregular. As a rule, they are marked by irregularity. They are mostly abdominal, rarely like true pains beginning in the sacral region and moving around to the region of the pubes. They may be caused by cramps in the abdominal wall, intestines, or in the distended bladder. They may be due to old inflammatory areas within the abdominal and pelvic cavities. They are frequent in cases in which there is marked bowel irregularity, and in conditions of over-fatigue. Some authors believe that they may be produced by irregular contractions of portions of the uterine wall. One important test is the condition of the uterine body during the pain. If there is no genuine contraction, the uterus will not become hard when pain is felt. This indication is not always reliable, however, since palpation may be unsatisfactory on account of the woman’s nervousness, her sensitiveness, or the thickness of the abdominal wall. If the cause be contractions of the uterus, partial hardening may be felt. TABLE FOR CALCULATING THE PERIOD OF UTERO-GESTATION.