One of the first things to strike us, and to suggest an application to human life, is the importance of Love, among these little creatures, for the health of the individual. The authors of _The Evolution of Sex_ say in one passage (p. 178): “Without it [conjugation], the Protozoa, which some have called ‘immortal,’ die a natural death. Conjugation is the necessary condition of their eternal youth and immortality. Even at this low level, only through the fire of love can the phœnix of the species renew its youth.” And again, in another passage (p. 277), referring to the conclusions of Maupas: “Already we have noted this important result, that conjugation is essential to the health of the species.” Thus it appears that, in these primitive stages, fusion more or less complete, or interchange of essences, leads to Regeneration and renewal of vitality—and this long before the distinct phenomena of sex appear. It leads to Regeneration first, and so collaterally, and at a later period, to Generation. Somehow—though it is not quite clear how—this view of the importance of love to personal health has been sadly obscured in later and Christian times. The dominant Christian attitude converted love, from being an expression and activity of the deepest human life and joy, into being simply a vulgar necessity for the propagation of the species. A violent effort was made to wrench apart the spiritual and corporeal aspects of it. The one aspect was belauded, the other condemned. The first was relegated to heaven, the second was given its _congé_ to another place. Corporeal intercourse and the propagation of the race were vile necessities. True affection dwelt in the skies and disdained all earthly contacts. And yet all this was a vain effort to separate what could not be separated. It was like trying to take the pigments out of a picture; to call the picture “good,” but the stuff it was painted with “bad.”