HUNTING AND FISHING RACES 135
(1) A survey of these races is undertaken to show the prevalence
of factors bearing upon fertility and elimination, and evidence
of (2) pre-puberty intercourse, (3) prolonged lactation, (4)
initiation ceremonies, (5) postponement of marriage, and (6)
abstention from intercourse is given. (7) Evidence of small
average size of family. (8) Among factors of elimination,
abortion, (9) infanticide, (10) warfare, (11) feuds, (12)
killing of old and sick, (13, 14) disease, and (15) child
mortality are investigated.