France patterned after the Roman law for a time and made criminal abortion punishable by inflicting the death penalty; during the French revolution this law was amended by imprisonment for life; and later, under Napoleon, in 1810, the law was again changed, and the punishment lessened. In England there has been a gradually growing moral sentiment to protect the defenseless child in its mother’s womb, so that to-day England has so amended her law that the fetus has the same protection in the uterus before as after quickening, so that a conviction for the procurement of criminal abortion at any time during gestation from conception until birth is _felony_ and punished by imprisonment or transportation. In Germany the law makes abortion a State prison offense, and public opinion is in such a healthy state there that anyone justly accused of this crime is quite sure to meet with a punishment. In America legislation on this subject differs widely in the different States. In Massachusetts the barbarous distinction, “before quickening and after,” was still recognized a few years ago, so that the crime of abortion before quickening was not an indictable offense. In some of the States the laws are stringent and conform with the physiological facts of fetal life, but, like most of our “good laws,” they are. observed only in the breach. The essential peculiarity in the process of reproduction is the absorption of a small cell of the male, the spermatozoon, by another small cell of the female, the ovum. This coalescence of the two, _male_ and _female_ cells, is the fertilization of the ovum, and constitutes _conception_. The spermatic fluid of the male holds in suspension a large number of very small bodies, or cells, which, from their usually remaining in active motion for some time after they have quitted the human body, have been erroneously considered animalcules. A more thorough familiarity with these bodies, and careful microscopic examinations, can distinguish nothing in the nature of structure within them. They are simply little oval, flattened, transparent cells between the one-six-hundredth and one-eight-hundredth of an inch in length, having a little thread-like “tail,” gradually tapering to a fine point. These measurements make the spermatozoa considerably larger than the average red blood-corpuscle, which is one-thirty-two-hundredths of an inch in diameter. The spermatic fluid of a single emission of a healthy male contains thousands of these little ciliated cells, the cilia or tails of which are seen in an active vibratile undulatory motion, in the field of the microscope, wriggling hither and thither, like a school of frightened fishes. This lashing motion is continued for hours, and under favorable circumstances for days. In the cases of microscopical examinations of vaginal secretions of married women, for causes of sterility, I was able to establish their activity thirty-six hours after marital relations.