About the middle of the fourteenth century there were, it seems, only eighteen principal castes or tribes among the non-Aryan Tamils as might be inferred from the saying பள்ளுப்பறை பதினெட்டு ஜாதியும் (the 18 castes inclusive of the Pallas and Paraiyas). Within the last five hundred years they have increased tenfold, on account of various causes which will be explained below.
The elements which contributed to the break up of the few Dravidian tribes into innumetable castes were, (1) food, (2) occupation, (3) religion, and (4) locality. The Dravidians of antiquity like the Vedic Aryans used to eat beef, pork, venison, mutton and fish, and as late as 250 A. D. even Brahmans of South India appear to have been meat-eaters. But under the humane influence of Jainism, the Brahmans had ceased long before the Pauranic period to eat any animal food, and some of their Dravidian neighbours followed suit. This, by the way, may be observed as a remarkable case, quite unique in the sociology of a whole people-the Brahmans-changing its habit from meat eating to vegetarianism. Killing of animals was condemned as a sin, the gravity of which increased according to their usefulness to the Brahman's personal comforts and religious offerings. Thus, the cow became the most sacred animal, because of her five products, panchagavyam, which were necessary for their food and sacrifice, and the killing of such an animal was and is still being considered one of the greatest of sins. It has given rise to an
