In spite of the bizarre and frequently repellent appearance of the cacti as seen under cultivation, in their barren homes they are in harmony with their surroundings, and add a characteristic, and even beautiful element to the scenery of the parched and generally desolate valleys and rocky slopes where they thrive best. Their blossoms are large, usually either white or brilliantly coloured, and expand in the hot, dry air, fully exposed to the intense sunlight, and present a freshness and vigour which tell of the abundant store of moisture within the thick rind inclosing their stems. The showy flowers are borne close to the body of the plant or at the ends or edges of the inflated pad-like leaves, and are scentless, except in the case of a few night-blooming species, and attract insects from afar by reason of the conspicuousness of their widely expanded corollas. The fruits also are usually conspicuous, and present many rich tints of red and yellow, which at a little distance give them the appearance of flowers. The fruit of several species are edible, and even delicious, especially when gathered fresh from the thorny stems and eaten on the desert, perhaps many miles from the nearest spring or stream. One species of cactus growing abundantly in Mexico and known as the cochineal-fig, is inhabited by the cochineal-insect, from which the highly prized dye of that name is obtained. A companion of the cacti in the arid region where they flourish best is the yucca, or Spanish bayonet, which sometimes attains the size of small trees and throws out several branches. Its leaves are stiff, thick-stemmed, and each one terminated by a sharp spine, as is well known from the many examples to be seen under cultivation in Europe and America. The flowers are white and borne in luxuriant showy spikes a foot or two in length, and sometimes give to dry, rocky slopes the appearance of a luxuriant garden. The cacti, yuccas, and associated plants of the most arid portions of the continent stand far apart, without mutual support or shelter, and find protection in their spines, thick rinds, and frequently acrid juices. Their colours are usually neutral, grayish green, rendered still more inconspicuous by the dust that settles on them, but their flowers are as a rule conspicuous, thus serving to attract pollen-bearing insects, and their fruits are in many instances brightly coloured, and furnish food for birds and other animals, which assist in the distribution of their seeds.