Matches between a man of higher and a woman of lower caste were called _anuloma_, or 'with the hair' or 'grain,' and were regarded as suitable and becoming.

Those between a man of lower and a woman of higher caste were, on the other hand, known as _pratiloma_ or 'against the hair,' and were considered as disgraceful and almost incestuous.

The offspring of such unions are held to have constituted the lowest and most impure castes of scavengers, dog-eaters and so on.

This doctrine is to be accounted for by the necessity of safeguarding the morality of women in a state of society where kinship is reckoned solely by male descent.

The blood of the tribe and clan, and hence the right to membership and participation in the communal sacrifices, is then communicated to the child through the father; hence if the women are unchaste, children may be born into the family who have no such rights, and the whole basis of society is destroyed.