=The subject of maternal impressions= is the cause of much anxiety during pregnancy. It is safe to assure the mother that it is nearly impossible to mark her child by emotional stress. There is no demonstrable nervous communication between mother and child, and most of the deformities that occur and are attributable to shock, etc., can be explained by our knowledge of intrauterine changes. Furthermore, the same deformities occur in lower animals, to which it is difficult to ascribe such high nervous organization. Many of the birthmarks, supposedly due to shock, occur too late in the pregnancy to affect the child, even if it were possible, for the child is completely formed before the fourteenth week. =The Determination of Sex.=—It is not possible to know in advance of delivery whether the child will be a male or a female. It is equally impossible to determine or even to influence the sex of the coming child. Many theories have been advanced, and much talent has been wasted in trying to solve this problem. Reasoning by analogy from the facts obtained from lower animals, the sex of the child is unalterably decided the moment conception occurs. The responsibility for the decisions seems to lie with the male cell. All we really know is that the sexes appear in the ratio of 100 girls to 106 boys. CHAPTER V ABNORMAL PREGNANCY After the diagnosis of pregnancy has been satisfactorily established, no further internal examinations are necessary in the absence of special indications, until about the thirtieth week. At this time a series of complete physical examinations may be required to determine the presentation and position of the child, the presence and rate of fœtal heart tones, the diameters of the head, the length and approximate maturity of the child, as well as the condition of the bony and soft passages of the mother. It is thus that an appreciation of the obstetrical problem is secured and a course laid out for its successful solution. Pregnancy is not a disease, but a normal function; but the woman is exposed, nevertheless, to many grave risks that are peculiar to her condition and to many complications accidental or otherwise which are more serious on account of her pregnancy. =The Toxæmias.=—The growing ovum brings about changes in the maternal metabolism that are manifested by characteristic symptoms which in other better known conditions are recognized as due to toxæmia. Therefore, while there is no positive proof as yet that these symptoms, arising during pregnancy, are toxæmic in origin, the evidence goes to show that they are; and, therefore, should be classified as toxic. Postmortem findings in eclampsia and pernicious vomiting such as extensive thromboses, cell necrosis, and interstitial hæmorrhages are very suggestive.