"Thus," says Darwin, "we have given to man a pedigree of prodigious length, but not, it may be said, of noble quality. The world, it has been often remarked, appears as if it had long been preparing for the advent of man; and this, in one sense, is strictly true, for he owes his birth to a long line of progenitors. If any single link in this chain had never existed, man would not have been exactly what he now is. Unless we wilfully close our eyes, we may, with our present knowledge, approximately recognize our parentage; nor need we feel ashamed of it. The most humble organism is something much higher than the inorganic dust under our feet; and no one with an unbiassed mind can study any living creature, however humble, without being struck with enthusiasm at its marvellous structure and properties." In considering the formation and perpetuation of the races of mankind, Darwin was again and again baffled. He could not decide that any of the physical differences between the races are of direct and special service to him, thus giving opportunity to natural selection to work. Hence he was led to study in detail the effects of sexual selection, especially as applicable to man. The greater part of "The Descent of Man" is occupied with tracing out what may be called the history of courtship in man and animals. The great variety of interesting subjects dealt with cannot be detailed here. We must only notice a few points about mankind which are of special importance. Darwin concludes that man's predominance over woman in size, strength, courage, pugnacity, and even energy was acquired in primeval times, and that these advantages have been subsequently augmented chiefly through the contests between men for women. Even man's intellectual vigour and inventiveness are probably due to natural selection, combined with inherited effects of habit, for the most able men will have succeeded best in defending and providing for their wives and offspring. Beards, beardlessness, voice, beauty are all related to sexual charm, and have been selectively developed. Early man, less licentious, not practising infanticide, was in several respects better calculated to carry out sexual selection than he is now; and thus we find the various races of men fully differentiated at the earliest date of historic records.