These encyclopedias are pervaded by a tone of literary scholarship. It was a peculiarity of Latin literature that philology was almost as old as poetry. The Roman poetry was a mere reflection of the Greek, the poets invariably knowing Greek and either translating from it or following Greek models. Poetry so produced was inevitably artificial and in need of elucidation. These conditions favored the rapid growth of criticism; grammar, word derivation, philology, antiquarian history were favorite studies from early times, engaging the attention even of leading Romans. There was even a sort of literary science; for example, Varro’s geography, which was meant to include the geographical allusions of the poets. A mass of scholarly lore was thus accumulated and this soon became unwieldy. It was the function of Varro and Verrius Flaccus especially to reduce this mass to order and to bring it into such shape that it could be referred to readily. To effect the latter object Verrius Flaccus introduced the method of alphabetical arrangement, using this for the first time in his great work _De Verborum Significatu_. These two writers gave, then, in their encyclopedic works a survey of the apparatus for literary criticism, including a sort of literary science, and the whole succession of encyclopedic writers was greatly influenced by the example which they set. In the works of Pliny and Suetonius, who followed Varro and Verrius Flaccus, natural science is brought into the foreground. The change, however, was but slight. The natural science of the Romans was anything but scientific; neither experiment, systematic observation, nor research had ever been practiced among them. Their science was an affair of books and was of an authoritative character. Even the poets were looked upon as possessing scientific knowledge and were seriously quoted to maintain scientific theses. There was no real distinction between the natural and philological sciences of the time, and therefore the encyclopedia of literary criticism was closely allied with that of natural science.