Changes in the Abdomen.—­ During the first two months of the pregnancy there is a flattening of the abdominal surface, due to the descent of the uterus into the pelvic cavity, thus slightly dragging the bladder downward and drawing the umbilicus inward.  In the latter part of the fourth month there is noticeable a slight abdominal enlargement, and the umbilicus is no longer sunken.  By the end of the fourth month the base of the uterus has risen two inches above the symphysis, and at the end of the thirty-eighth week it touches the lower extremity of the breast-bone; the umbilicus has been for many weeks protruding; during the last two weeks of pregnancy the uterus again descends and the woman feels more comfortable.

On the inspection of the abdomen of a pregnant woman there will be noticed a brown line which extends from the umbilicus to the pubes, and all over the surface the presence of striae, or long purple grooves, due to the distention of the abdomen; on the sides of the abdomen and down the thighs, red, blue, or white markings, like cicatrices, may be seen.

Quickening.—­ Quickening is the sensation experienced by the mother as the result of the active fetal movements of the child in the womb.  These movements are first felt between the eighteenth and the twentieth week; the common rule is that quickening occurs at the middle of pregnancy; that is, at four and a half months.  As pregnancy advances these active motions increase in frequency and become more marked.  When felt or seen by the physician, as can be done in the sixth month, fetal movements constitute a positive sign of pregnancy.

The Determination of Sex at Will.—­ Although this has always been a question of great interest, and the subject of much experimentation, no rule can as yet be given by which the parents can know in advance of the birth of the child what the sex will be.  Dr. Schenck’s theory is that the ruling factor in determining the sex is the food partaken of by the mother.

Furst believes that the differentiation may occur before, during, and a little while after the impregnation; that the chances of the development of one or another sex in one and the same woman may vary before final differentiation occurs.  It is impossible to determine the sex of the embryo before the tenth week of fetal life.  The cause of the differentiation, he believes, lies largely in the good or bad state of the health of the parents; in the first instance there being an excess of females, and in the latter an excess of males, relatively speaking.  He believes that there is an excess of male children when conception takes place during the post-menstrual anemia.  He has investigated one hundred and ninety-three cases carefully in regard to the probable date of conception after menstruation, and there is a notable increase of male births over female in the cases where conception occurred in the first five days after menstruation; that is to say, where the woman is not so well nourished as later.