Yield and profitableness are discussed, and the practice of thinnings is known, but only for the purpose of removing and using the dead material. Forest protection was poorly developed: of insects little, of fungi no knowledge existed. Hand-picking was applied against caterpillars, also ditches into which the beetles were driven and then covered; the use of hogs in fighting insects was also known. That goats were undesirable in the woods had been observed. Some remarkable precocious physiological knowledge or rather philosophy existed: it was recognized that frost produces drought and that a remedy is to loosen the soil, aerating the roots, to drain or water as the case might require, and to prune; but also sap letting was prescribed. Against hail, dead owls were to be hung up; against ants, which were deemed injurious, ashes with vinegar were to be applied, or else an ass’s heart. Curiosities in wood technology were rife and many contradictions among the wood sharps existed, as in our times. Only four elements, earth, water, fire, air, composed all bodies; the more fire in the composition of a wood, the more readily would it decay. Spruce, being composed of less earth and water but more fire and air, is therefore lighter than oak which, mostly composed of earth, is therefore so durable; but the latter warps and develops season splits because on account of its density it cannot take up readily and resists the penetration of moisture. Wood impregnation, supposed to be a modern invention, was already practiced; cedrium (cedar oil) being used as well as a tar coating or immersion in seawater for one year, to secure greater durability. 4. _Literature._ As regards literature, we find in Greece, besides what can be learned incidentally from the historians _Herodotus_ and _Xenophon_ and from the natural history of Aristotle, the first work on plant history and wood technology, if not forestry, in 18 volumes by _Theophrastus_ (390-286 B.C.), a pupil of Aristotle and Plato.