They possess very little vital power, and readily succumb to diseases, suffering much from febrile disorders, which give rise to pulmonary complaints--the chief cause of mortality among them. Very few reach the age of fifty, and the average duration of life is little over twenty years. Of the lesser ailments, skin diseases are very common. Measles, to which over 20 per cent. of the population fell victims in 1877, was followed by an outbreak of syphilis, both introduced by convicts. The latter disease has caused much injury, and its spread has, it is believed, been greatly accelerated by the custom prevailing of the women suckling each other's children. The "sense of shame" is but little developed, and the natives pay no attention to their own nudity, although by nature they are modest. Of the various objects worn, those only coming under the heading of clothing are the aprons or leaves worn with the girdle by the women, and always carefully adjusted. Previous to marriage, which is not permitted to those between whom any degree of consanguinity can be traced, unchastity is the rule with both sexes. Births out of wedlock, however, are considered discreditable, and marriage generally follows on a girl becoming _enceinte_, in which case there seems no objection on the part of the lover to become the husband. Once married, conjugal fidelity until death is the rule, and bigamy, polygamy, and divorce are unknown. Restrictions from various tabooed articles of food, which begin at puberty and often last for years, are brought to a conclusion after a long series of initiatory ceremonies undergone by both sexes. When a death occurs, the corpse is buried with a method and ceremonies differing somewhat according as to whether it be adult or child;[102] and after some months, during which the encampment in which the death took place is deserted, the body is exhumed, and the bones cleaned and made into souvenirs, which are distributed to relatives and friends. Numerous superstitions are extant among them, and there is credence in wizardry. No form of worship is to be found; but there exists a belief in a spiritual being, called _Púluga_, the Creator; and in evil spirits, _Érem-chaugala_, the spirit of the woods; and _Juruwinda_, the spirit of the sea, the first of whom causes sickness and earthquakes, the latter cramp; both are demoniacal. There are also a host of minor devils, who are self-created; none of the demons are under the control of _Púluga_.[103] They make no attempt at trading in the natural products of their islands, and manufacture nothing but the weapons, personal ornaments, implements, and utensils required for their own use. They have some knowledge of pottery, though not of the wheel, and make rude pots, which they ornament with patterns of wavy lines before baking. No true musical instruments exist, but a rude sounding-board is constructed, on which they accompany songs by beating with the foot.[104]