Indologists:
There are many reasons why rice is used on
vermillion when applying a tilak. Some reasons are simple or practical: rice is
small and white and stays on the tilak.
But the more important reason is husked rice, as
opposed to other cereals or lentils, does not sprout. It is beyond growth and
decay and therefore complete, whole.
Anthropoligically rice is more ancient than wheat in India.
The Dravidian connection cited by you is an interesting one.
Th tilak which is a bindu is analogous to the
anusvara, a sign of purnatva or fullness. A grain that is full and complete, and
which is not susbject to birth and death through growth, only can augment the
tilak and none other.
I would welcome any comments.
Harsha V. Dehejia