And again:  According to their own account, the Indian nations were divided into tribes for no other purpose than that no one might ever, either through temptation or mistake, marry a near relation, which at present is scarcely possible, for whoever intends to marry must take a person of a different tribe.*

(Footnote.  Ibid.)

The same feeling was remarked by Dobrizhoffer in South America; for, speaking of an interview with a native tribe to whom he was preaching, he says: 

The old man, when he heard from me that marriage with relations was forbidden, exclaimed, “Thou sayest well, father, such marriages are abominable; but that we know already.”  From which I discovered that incestuous connexions are more execrable to these savages than murder or robbery.*

(Footnote.  Account of the Abipones Volume 1 page 69.)

PUNISHMENT OF SECONDARY OFFENCES.  ORDEAL AND PUNISHMENT FOR OTHER
TRANSGRESSIONS.

Any other crime may be compounded for by the criminal appearing and submitting himself to the ordeal of having spears thrown at him by all such persons as conceive themselves to have been aggrieved, or by permitting spears to be thrust through certain parts of his body; such as through the thigh, or the calf of the leg, or under the arm.  The part which is to be pierced by a spear is fixed for all common crimes, and a native who has incurred this penalty sometimes quietly holds out his leg for the injured party to thrust his spear through.

When a native, after having absconded for fear of the consequences of some crime which he has committed, comes in to undergo the ordeal of having spears thrown at him, a large assemblage of his fellows takes place; their bodies are daubed with paint which is put on in the most fantastic forms, their weapons are polished, sharpened, and rendered thoroughly efficient; at the appointed time young and old repair to the place of ordeal, and the wild beauty of the scenery, the painted forms of the natives, the savage cries and shouts of exultation which are raised as the culprit dexterously parries, or by rapid leaps and contortions of his body avoids the clouds of spears which are hurled at him, all combine to form a singular scene to which there is no parallel in civilized life.  If the criminal is wounded in a degree judged sufficient for the crime he has committed his guilt is wiped away; or if none of the spears thrown at him (for there is a regulated number which each may throw) take effect he is equally pardoned.

But no sooner is this main part of the ceremony over than two or three duels take place between some individuals who have quarrels of their own to settle; after these combatants have thrown a few spears some of their friends rush in and hold them in their arms, when the etiquette on such occasions is to struggle violently for a few minutes, as if anxious to renew the contest, and then to submit quietly to superior force and cease the combat.