We owe to Lloyd Jones an important contribution to the knowledge of chlorosis in its physiological or normal relationships. He has shown that chlorosis is but the exaggeration of a condition that is normal at puberty (and, in many women, at each menstrual period), and which, there is good reason to believe, even has a favorable influence on fertility. He found that light-complexioned persons are more fertile than the dark-complexioned, and that at the same time the blood of the latter is of less specific gravity, containing less hæmoglobin. Lloyd Jones also reached the generalization that girls who have had chlorosis are often remarkably pretty, so that the tendency to chlorosis is associated with all the sexual and reproductive aptitudes that make a woman attractive to a man. His conclusion is that the normal condition of which chlorosis is the extreme and pathological condition, is a preparation for motherhood (E. Lloyd Jones, "Chlorosis: The Special Anæmia of Young Women," 1897; also numerous reports to the British Medical Association, published in the _British Medical Journal_. There was an interesting discussion of the theories of chlorosis at the Moscow International Medical Congress, in 1898; see proceedings of the congress, volume in, section v, pp. 224 et seq.). We may thus, perhaps, understand why it is that hysteria and anæmia are often combined, and why they are both most frequently found in adolescent young women who have yet had no sexual experiences. Chlorosis is a physical phenomenon; hysteria, largely a psychic phenomenon; yet, both alike may, to some extent at least, be regarded as sexual aptitude showing itself in extreme and pathological forms. FOOTNOTES: [251] _Genèse et Nature de l'Hystérie_, 1898; and, for Sollier's latest statement, see "Hystérie et Sommeil," _Archives de Neurologie_, May and June, 1907. Lombroso (_L'Uomo Delinquente_, 1889, vol. ii, p. 329), referring to the diminished metabolism of the hysterical, had already compared them to hibernating animals, while Babinsky states that the hysterical are in a state of subconsciousness, a state, as Metchnikoff remarks (_Essais optimistes_, p. 270), reminiscent of our prehistoric past. [252] Professor Freud, while welcoming the introduction of the term "auto-erotism," remarks that it should not be made to include the whole of hysteria. This I fully admit, and have never questioned. Hysteria is far too large and complex a phenomenon to be classed as entirely a manifestation of auto-erotism, but certain aspects of it are admirable illustrations of auto-erotic transformation.