The fertility of the criminal a greater danger to society than his depredations.--Artificial sterility of women.--The menopause artificially induced. Untoward results.--The physiology of the Fallopian tubes.--Their ligature procures permanent sterility.--No other results immediate or remote.--Some instances due to disease.--Defective women and the wives of defective men would welcome protection from unhealthy offspring. CHAPTER XII.--SUGGESTIONS AS TO APPLICATION p. 118 The State's humanitarian zeal protects the lives and fosters the fertility of the degenerate.--A confirmed or hereditary criminal defined.--Law on the subject of sterilization could at first be permissive.--It should apply, to begin with, to criminals and the insane.--Marriage certificates of health should be required.--Women's readiness to submit to surgical treatment for minor as well as major pelvic diseases.--Surgically induced sterility of healthy women a greater crime than abortion.--This danger not remote. CONCLUSION p. 124 THE FERTILITY OF THE UNFIT. * * * * * INTRODUCTION. Biology is the Science of Life. It seeks to explain the phenomena of all life, whether animal or vegetable. Its methods are observation and experiment. It observes the tiny cell on the surface of an egg yolk, and watches it divide and multiply until it becomes a great mass of cells, which group off or differentiate, and rearrange and alter their shapes. It observes how little organs unfold themselves, or evolve out of these little cell groups--how gradual, but how unvarying the change; how one group becomes a bone, another a brain, another a muscle, to constitute in three short weeks the body of a matured chick. Those little tendons like silken threads, that run down those slender pink legs to each and every toe, and move its little joints so swiftly that we hardly see them--that little brain, no bigger than a tiny seed, in which is planted a mysterious force that impels it to set all those brand-new muscles in motion, and to dart after a fly with the swiftness of an arrow--all this wondrous mechanism, all this beauteous structure, all this perfection of function, all this adaptation to environment, have evolved from a few microscopic cells in three short weeks. Biology is the science that observes all this, and enunciates the law that the life history of this animal cell, _i.e._, its history from a simple unicellular state in the egg, to its complex multicellular state in the matured chick, represents the history of the race to which the chick belongs. If we could trace that chicken back through all its ancestry, we would discover at different periods in the history of life upon the globe (about 100 million years, according to Haeckel) exactly the stages of development we found in the life history of the chick, and arrive at last at a primordial cell.