Should a child be born with any natural deformity it is frequently killed by its parents soon afterwards.

In the only instances of this kind which have come within my own knowledge the child has been drowned.
LUNATICS AND IDIOTS.
Idiots are rarely found amongst the natives; in two cases I however observed persons of very deficient intellect.

Mad people are unknown, and this very naturally, for very few freaks of madness could be committed by a lunatic ere he would fall a sacrifice to the violence and indignation of his fellows.

Persons of very delicate and feeble constitutions are also rare, as those who survive the hardships to which they are exposed in their childhood must possess an iron frame.

The deaths amongst the children, particularly during early infancy, are as far as I can judge much more numerous in proportion to the number of births than they are in civilized nations.
INFLUENCE OF POLYGAMY ON SOCIAL HABITS.
The social habits of the natives of Australia are necessarily modified by the extent to which polygamy is permitted and practised amongst them.