These types are, however, more or less delicate, and are weak in constitution and easily killed. To prevent such variations those who wish to keep a race of seed pure are careful to keep it growing on poor land. In 1596 the Hyacinth (_Hyacinthus orientalis_) was introduced from the Levant. In 1597 there were four varieties, and in 1629 eight kinds were known, but in 1768 two thousand forms of hyacinth were named and described. Besides selection, the method of hybridizing or crossing is often used in order to obtain new or valuable strains. Generally both hybridizing and crossing are employed. This method has long been practised. Bradley, in 1717, writes as follows: "A curious person may by this knowledge produce much rare kinds of plants as have not yet been heard of"; and, in fact, peaches, potatoes, plums, strawberries, and savoys have all been greatly improved by hybridizing and selection.[126] By crossing certain kinds of corn, such as the Chinese Oat and the wild European Oat, varieties have been produced by Messrs. Garton which at the Highland and Agricultural Society's trials produced 84, 87, and 99 bushels per acre, as compared with 58 bushels yielded by the ordinary Scotch Oat.[127] With potatoes also astonishing results have been got. [126] Masters, _Nature_, July, 1899. [127] _Journal Farmers' Club_, February, 1900. [Illustration: _Queensland Government Photo_ SUGAR CANE IN QUEENSLAND The cart is being loaded up to carry the canes to the factory, where it will be crushed by the latest and most perfect machinery.] One single potato was sold for £50 not very long ago. The Potato, like the Indian corn, tobacco, and a few other plants, is an inhabitant of the New World. Of other cultivated plants the native country is not known. No one knows where, for instance, Sugar-cane was first cultivated, but it has nine Sanskrit names, one of which, _khand_, is, or has probably at one time been familiar to us as sugar-candy. It was well-known when the Institutes of Manu were written, but that may have been somewhere between 2000 B.C. and A.D. 20. One of the Hindu Indian deities, Kámadeva, who corresponds to Cupid, the God of Love, carries a bow made of sugar-cane, with a string which is composed of bees. "He bends the luscious cane and twists the string With bees: how sweet! but ah! how keen their sting, He with five flowerets tips the ruthless darts Which through five senses pierce enraptured hearts."