"When a boy has attained the age of fourteen or fifteen years he absents himself from his father's lodge, lying on the ground in some remote or secluded spot, crying to the Great Spirit, and fasting the whole time. During this period of peril and abstinence, when he falls asleep, the first animal, bird, or reptile, of which he dreams, he considers the Great Spirit has designated for his mysterious protector through life."[149] Similar ceremonies are described by Livingstone as existing among the South African tribes. These customs are too widespread, and bear too great a similarity to be described with reference to many races. The variations are unimportant, and such as they are they may be studied in the pages of Hall, Frazer, and numerous other writers. With girls the measures adopted are of a more elaborate character than is the case with boys, because, for reasons already stated, the occurrence of puberty in girls gives the supernatural act a more startling and significant character. Hence the strict seclusion of girls almost universally practised among uncivilised peoples. The precautions taken indicate, as Hartland points out, that they are at this period not merely charged with a malign influence, but are peculiarly susceptible to the onset of powers other than human. And with a modification of language the same idea has persisted down to our time, even amongst those who would reject with indignation the statement that savage ideas concerning the nature of puberty form the real basis of their own mental attitude.