It remained for the elder Pliny, however, in his wonderful work on natural history, written in the first century of the Christian era, to make the most remarkable reference to cork to be found in ancient literature: “The cork oak is but a very small tree and its acorns of the very worst quality * * *; the bark is its only useful product, being remarkably thick, and if removed will grow again * * *. This substance is employed more particularly attached as a buoy to the ropes of ships’ anchors and the drag-nets of fishermen; it is used also for the bungs of casks and as a material for the winter shoes of women.” Cork jackets--life-preservers--are mentioned by Plutarch. Thus five of the principal functions which cork fills in the world to-day were recognized two thousand years ago. In the fifteenth century glass bottles were introduced, which gave such great impetus to its general use that the real beginning of the cork industry may properly be said to date from that period. Some conception of its importance to-day may be gathered from the fact that the importations of the United States of crude and manufactured cork now aggregate almost $5,000,000 in value annually. [Illustration: Cork Strippers’ Camp] [Illustration: Stripping the Trees] [Illustration: Gathering the Bark] [Illustration: Cork Tree’s Foliage] The word _cork_ is derived from the Latin _cortex_, meaning bark, and the study of its origin and manufacture leads at once to those romantic countries bordering the Mediterranean Sea. Spain and Portugal divide honors among the nations of the world so far as yield of raw material is concerned, with perhaps the advantage leaning slightly to the latter. The cork-producing territory covers practically the whole of Portugal, sweeps toward the east through the southern districts of Spain known as Andalusia and Estremadura, thence northeast, embracing thousands of acres of forests in Catalonia. Algeria, with Tunis, ranks next in importance in yearly tribute of bark, southern France, including Corsica, following closely after. Italy, too, with the help of Sardinia and Sicily, continues to be quite a factor in meeting the demand for the crude material, while across the Strait of Gibraltar the sun-scorched forests of Morocco are as yet undeveloped. The total area covered by cork forests is estimated at from four to five million acres, while the annual production of bark is declared to be not far from fifty thousand tons. Although no official statistics are obtainable, these figures approximate the truth. In Portugal and Spain, particularly in Catalonia, which is probably the greatest cork manufacturing district in the world, a large portion of the corkwood produced goes to supply domestic factories, where more and more machinery is being introduced every year. With these exceptions, however, the major part of the yield is exported to the United States, England, France, Germany, Austria, Russia, Denmark, or Sweden, to be