It is now known that, quite apart from any motive of concealment of the true paternity of their offspring, some of the native tribes of Australia have the belief that, as the regular and normal thing, children are begotten by strange fairy-like spirits which haunt the rocks and trees of certain localities and enter the future mother as she passes by these haunted rocks and trees. These Australian "black fellows" hold that the human father counts for nothing in the matter. The belief of these Australian savages is referred to by writers on the subject (Mr. Andrew Lang and others) as "the spiritual theory of conception." There are some reasons for thinking that this curious theory and the accompanying ignorance as to the natural causes of conception were widely spread among primeval men. The fact that most trees are fertilised by the wind (which carries to their female flowers the invisible powder, or pollen, of the male flowers, conveyed in the case of smaller plants which have gay-coloured flowers by bees and butterflies) may have been noticed by primitive man, and have started the belief that there are fertilising spirits or demons in the air. However the fancy arose, it is only a parallel to the strange fancies as to spontaneous generation of all sorts of animals and plants current 200 years ago among civilised men. And, further, it is worth noting that the uncanny belief in the "incubus" which was generally prevalent in the Middle Ages may possibly be considered as a survival in (or incursion into) Europe of the primitive spiritual theory of all human conception, and of the fertilising activity of the haunting spirits of the air which was held by primeval man, and is still found in full force among the Arunta tribes of Australia. "Ore omnes versae in Zephyrum stant rupibus altis Exceptantque leves auras et saepe sine ullis Conjugiis vento gravidae, mirabile dictu." Georgic iii. 275. (Facing the west on lofty rocks All stand and sniff the buoyant breeze And often--marvellous to tell-- Without conjunction with a sire, Bear young engendered by the wind.) CHAPTER XV THE PYGMY RACES OF MEN