* * * * * In the widest treatment of the maternal instinct it will not suffice to narrow our attention to the function of human motherhood, or to take up our study of the conditions relating to the mother and the child as we find them amongst us to-day. Were I to do this and to attempt at once to bring forward my own views, with the reforms that I wish for in this matter, my work would be as a building without a firm foundation, more or less uncertain, and for this reason valueless. To get a proper grip of all that is here concerned we must understand that the maternal instinct is the deepest and strongest instinct in woman. It is in the emotions and actions either directly arising from or connected with motherhood that we find the real difference between the sexes. In its essence the parental instinct belongs to woman alone. The male may be infected with its energy—we witness this among birds, as well as in humbler animals, where the duties of caring for offspring are shared and, in some cases, carried out by the male alone; but man possesses, as yet, its faint analogy only. It is the most primary of all women’s qualities.[9] Now, why is this? Why is woman’s being so much more strongly infected with motherhood than the man’s with fatherhood? It is a question not so readily to be answered as it might appear. If we find the explanation in the intimate connection between the mother and the child we have not, I think, exhausted the matter. We must not forget that other questions remain behind unanswered, all centring round the one question to which an adequate answer is so difficult to find: How has this arisen? The fact has to be explained that the sharp separation in the parental impulse and the parental duties, so strong amongst us, has not always existed; that there are many examples in the history of life which show an exactly opposite condition. To find the clue it will thus be necessary to turn our attention to the earlier stages of life where, in particular among insects, reptiles, fishes, and birds, we find the widest possible range of difference in the expression of the parental instinct and the most varied relations existing between parents and offspring. Here indeed, among these pre-human parents, we can study the maternal instinct in the making. There are many new and strange facts for us to learn.