union may seldom be attained to, the great majority of married couples manage to jog on together, and bring up families in comparative comfort and respectability. Evidently, however, in many cases the weaker party does not get fair play, and the laws which are the result of centuries of male legislation are often too oblivious of the maxim that what is ‘sauce for goose is sauce for gander.’ Improvement, however, is coming from the growth of the more healthy public opinion which stigmatises any invasion of woman’s real rights, and any attempt on the part of her natural protector to bully and tyrannise, as utterly disgraceful; and the waves of this public opinion are slowly but surely sapping the cliffs of legal conservatism, and forcing the intrenchments of stolid injustice behind ermine robes, horsehair wigs, and obsolete Acts of Parliament. CHAPTER IX. PRIMITIVE POLARITIES—HEREDITY AND VARIATION. Heredity in simple forms of life—In more complex organisms—Pangenesis—Varieties how produced—Fixed by law of survival of the fittest—Dr. Temple’s view—Examples: triton, axolotl—Variations in individuals and species—Lizards into birds—Ringed snakes—Echidna. As the earth is kept in an orbit, which makes life possible by the balance of the antagonist centripetal and centrifugal forces, so is that life evolved and maintained by the balance of the two conflicting forces of heredity and variation. Heredity, or the principle which makes offsprings resemble their parental organisms, may be considered as the centripetal force which gives stability to species; while variation is like the centrifugal force which tends to make them develop into new forms, and prevents organic matter from remaining ever consolidated into one uniform mass. As regards heredity, the considerations which have been advanced in the last chapter, on the origin of sex, will enable the reader to understand the principles on which it is based. When a moneron, or living piece of pure protoplasm, or its successor the nucleated cell, propagates itself by simple division into two equal parts, it is obvious that each half must, in its atomic constitution and motions, exactly resemble the original. If amœba A divides into amœbæ B and C, both B and C are exact facsimiles of A and of one another, and so are the progeny of B and C through any number of generations. They must remain identical repetitions of the parent form, unless some of them should happen to be modified by different actions of their surrounding environment, powerful enough to affect the original organisation.