Far from being comparatively rare, sports are very common among cultivated plants, al most every species of importance furnishing in stances. Among well-known bud-sports: the purple or copper beech, purple-leaved plums, and many weeping, variegated and cut-leaved trees and shrubs, are familiar examples. The perle des jardins rose has given rise to several commercially important bud-varieties. The moss-roses are bud-sports. The °mixing* of potatoes in the hill is also well known. Among plants propagated by seeds instances are legion — tomatoes, cabbage, corn, parsley, onions and a host of garden flowers. Probably the most striking instance of a plant producing both bud sports and seed-sports of value is the peach. Occasionally a seed will produce a smooth skinned fruit popularly called a nectarine, which in turn may produce either a nectarine or a peach. Certain branches of the peach tree may produce nectarines and vice-versa. Russet ap ples are sometimes seen upon greening trees. The sports may occur in any part of the parent plant — roots, tubers, rhizomes, stems, flowers, leaves, seeds and even buds upon the stem or the roots.
Another practical application of the tendency to sport among plants is the grafting of fruit trees with scions taken from the "bearing wood" of specially prolific or precocious trees of any particular variety. Such scions usually com
mence to bear earlier, or produce more regu larly, or both, than scions taken from shaded portions of the same parent trees or from un productive individuals.
One of the common troubles with sports is self-sterility. This is scarcely important ex cept with fruit trees where, if large blocks of one kind of tree are planted remote from other varieties that blossom at the same time, little or no fruit will be set. See paragraph Varie ties tinder title APPLE.
Sports are to be distinguished from rever sions in which the individual seems to hark back to the general form of its more or less distant ancestors. They must also be separated from cases of atavism (q.v.) in which the progeny exhibit a character not typical of their race, species or genus but characteristic of an allied ancestral race. Instances of reversion (q.v.) are the loss of the bulbous root of turnips and the "head" of cabbage which "run W ild"; of atavism, the occasional appearance of several-toed horses, whose feet somewhat re semble the three-toed foot of the horse of Tertiary time. See BREFDING ; Bon; HFREDITY ; HYBRIDITY ; NT. SELECTION ; VARIATION, and consult the authorities cited under them.