=The heart= is slightly hypertrophied on the right side and blood pressure somewhat raised. A marked increase in blood pressure is suggestive of eclampsia. =The thyroid gland= enlarges frequently, both as a consequence of menstrual irritation and of pregnancy. Goiters may show an increase of development, which remains after labor. =The urine= is diminished in amount, but increased in frequency of evacuation. The bladder is more irritable during the first and last months, and micturition may be painful and unsatisfactory. The kidneys must be watched carefully during gestation. =The nervous system= is disordered in most women, but especially in those of neurotic tendencies. Irritability, insomnia, neuralgia of face or teeth, or perversion of appetite in the so-called “longings” are the more common manifestations. Cramps occur in the muscles of the legs, owing to varicose veins or pressure upon the lumbar and sacral plexus of nerves. =The lungs= are crowded by the growing uterus and the respiration interfered with. =The liver= is enlarged, but functionally it is less competent, and constipation is common. It is probable that most of the changes enumerated above are due to the circulation through the body of some definite product of fœtal activity, which is more or less toxic in character. The more pronounced effects of this toxin will be studied under the abnormal conditions of pregnancy. Generally, if the pregnancy is normal, the whole body responds to the stimulating influence. After the nausea and vomiting of the early months subside, the woman feels energetic and ambitious. She is eager to do something at all times and feels fatigue but slightly. Music, literature or housework engages her attention and is zealously and joyfully practiced. The world seems bright and the thought of her labor does not bring solicitude, but pleasant anticipations. The body fills out in all directions and the woman takes on the appearance of maturity. DIAGNOSIS OF PREGNANCY The presence of pregnancy is naturally determined by the recognition of those changes in the maternal system which the growing ovum produces. During the _second half_ of the period the fœtus can be made out distinctly by palpation, or by its movements, and the heart tones observed by auscultation. During the _first half_ this is impossible and the diagnosis must be made from subjective symptoms elicited from the patient and upon physical signs observed by the physician.