division of akam and puṛam, but also about the four regions. As literary output increases there is always room to draw up more and more rules for the benefit of students and aspirants who desire to compose poetry. They found the former codification inadequate in so far as it was too general. It had limited a certain class of poetry to a certain region, but this later codification went a step further and prescribed also the hour or hours of day and the season of the year most suitable for poems of each class.

A further stage in codification was reached when in the course of years it was found that a large number of poems which could not be conveniently classified under the five heads proved a problem to redactors. It was to meet this difficulty, especially in the puṛam division, that two more "landless divisions" were invented in akam poetry with suitable opposites in puṛam poetry. These were peruntiṇai or passion, and kaikkilai or one-sided and unrequited love. These might occur in any of the five regions as would their puṛamopposites, kaañci signifying the transient state of wordly things, and paaṭaantiṇai comprising all panegyric poetry. When compared with the subject-matter of vaahai, it looks as if paṭaan was a subsequent addition to include the enormous output of panegyric poetry that arose at a later stage of Tamil civilization when Tamil kings and Tamil chiefs had court poets.

These seven divisions of poetry with their subdivisions which we have explained, were already long existing and had been crystallized in many works of rhetoricians, when Tolkaappiyar wrote his porulatikaaram. That a long period must have passed between the first attempts of the Tamil bard and the composition of Tolkaappiyam must be evident to every one who examines the historical development of Tamil poetry.

Tolkaappiyar's predecessors themselves had foreseen that these rules regarding flora and fauna and the manifestations of Nature in sun and sky and stars could not be followed too strictly by poets, nor too meticulously by redactors. Hence they provided for exceptions to the rules, and certain breaches of the ordinary poetic conventions were permitted under the head of "regional interchange"..

The "essential theme" of one region could not be attributed