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.4

The horror of incest is thus plainly of social derivation. With reference to inclination and passion, as related to the intimate contact of near kin, it may be said that in its natural course, without the imposition of a habit system, this would sometimes act in one way and sometimes in the other; but exogamy as a system seems to be the result of a social policy, as stated by Tylor.

4Russell, R.V.n/an/an/an/a, , 1: 29 (The Macmillan Company. By permission).