Here the common ground of belief ceases, and each writer branches off upon his own peculiar line of argument, appropriating and arranging the facts observed by explorers and investigators in the various lines of inquiry according to his own preconceived notions, or as best suits the particular scheme of development which he essays to establish. In the following pages the attempt will be made to show that the facts which in these later years have been brought to light concerning the development of the human race are in strict accord with the facts as enunciated by scientists relative to the development of the orders of life below man, and that together they form a connected chain of evidence going to prove not only that the higher faculties had their origin in the female but that the progressive principle has also been confided to her. CHAPTER II THE RELATIONS OF THE SEXES AMONG EARLY MANKIND We have seen that an investigation of the instincts and habits of creatures lower in the scale is necessary to an understanding of the relations which must have existed between the sexes among primitive races. Among birds and mammals, the greater differentiation of the nervous system and the higher pitch of the whole life is associated with the development of what pedantry alone can refuse to call love. Not only is there often partnership, co-operation, and evident affection beyond the limits of the breeding period, but there are abundant illustrations of a high standard of morality, of all the familiar sexual crimes of mankind, and every shade of flirtation, courtship, jealousy, and the like. There is no doubt that in the two highest classes of animals at least, the physical sympathies of sexuality have been enhanced by the emotional, if not also intellectual, sympathies of love.[52] [52] Geddes and Thomson, _The Evolution of Sex_, p. 266. It has been observed that among the orders of life below mankind, except among polygamous species, the female chooses the individual which is best endowed—the one whose beauty appeals to her æsthetic taste, or which through his stronger development is best fitted to assist her in the office of reproduction. Among the more intelligent species of birds, genuine affection has been observed, strict monogamy and life-long unions having been established between mated pairs. Among others, although the conjugal bond is not life-lasting, so long as the mother-bird is caring for her brood, constancy to one another is the undeviating rule. We are assured that with the female Illinois parrot, “widowhood and death are synonymous,” and that “when a wheatear dies, his companion survives him scarcely a month.”[53] [53] Letourneau, _The Evolution of Marriage and the Family_, p. 27.