[1] Charles Richet, “De la Variation mensuelle de la NatalitÉ,” 1916, Comptes rendus Acad. Sciences, Paris, pp. 141-149 and 161-166.

[2] By this I mean the motherhood which carries and protects the developed young within the mother’s body, unlike that of the lower animals, such as fishes, which leave the eggs to their fate.

[3] In this, and in most of the generalisations found in this book, I am speaking of things as they are in Great Britain. While to a considerable extent the same is true of America and the Scandinavian countries, it must be remembered all through that I am speaking of the British, and primarily of our educated classes.

[4] That is to say, repeating the history of our very early ancestors, where the female probably felt some resentment towards the male who had encompassed her maternity, and who most certainly would live apart from her and not in the ordinary contact of a united life.

[5] This book has been reprinted in a modern expurgated and mutilated edition, which deprives the reader of the most valuable portions of the author’s work. I should advise readers to see one of the original early editions if they desire to read the book intended by the author for the public.

[6] Balzac: Physiologie du Mariage.

[7] Charles Fourier, Leipzig, 1808.

[8] The sow normally breeding once a year, artificially forced to breed two or three times a year. Its appearance is proverbial.

[9] This has been reported to me by travellers and others, but I cannot get an authoritative scientific record for the fact.

[10] I refer the reader to that poignant book, Maternity, Letters from Working Women, collected by the Women’s Co-operative Guild. Bell, 1915.

[11] At the request of many readers this conversation was published in the Sunday Chronicle.