Page:The New International Encyclopædia 1st ed. v. 19.djvu/675

* TWILLINGATE. 583 is a prosperous fishins centre. Population, in 1801, 3585; in 1901, 3542. TWIN-FXOWER. A hardy, trailins; ever- green plant of tlio natural order C'aprifoliaceie. It i.s a favorite in rockeries on account of its dainty, bell-shaped, nodding, pink or white, fra- TWISS. TWIN FLOWER {LiDBxa borealis). grant fiowers, which appear during midsummer in pairs upon erect, slender stems. It thrives best in open, peaty soil and in shade. In the woods it may be found as far south as Maryland and the mountains of California, but is more common northward. TWI'NING, Kinsley (I832-I90I). An American clergyman and editor, born at West Point. N. Y. He graduated at Yale in 1853, at Y'ale Theological Seminary in 1856. was a resi- dent licentiate at the Andover Theological Sem- inary in 1857, and from 1857 to 1876 occupied various Congregational pulpits. In 1880-98 he was literary editor of the New York Independent. and in 1898 became literary editor of the Evan- gelist. He was one of the founders of the Reform Club of New York City. TWINING PLANTS. Plants whose axes are coiled about slender supports, e.g. common morning-glory and hop. In most cases the support must be slender (less than 15 centimeters in diam- eter), though some tropical plants coil about thick tree trunks, and others climb in a some- what similar fashion by partial twining. (See Li.NAS.) The direction of twining varies with different plants, being either clockwise or coun- ter-clockwise. While the direction of twining is usually constant in the same species, some twin- ers coil in either direction. The direction is not constant, however, among members of the same family, nor even among different species of the same genus. The cause of twining has long been a problem of great difficulty. The most satisfactory expla- nation seems to be the following: Twining stems are endowed with a sensitiveness to the action of gravity, which may be distinguished as lateral geotropism (q.v.). The stem at first grows erect (on account of negative geotropism), but through unequal growth, causing nutation (q.v.), soon in- clines to one side. At this period of its develop- ment, the flanks (i.e. the sides of the stem now on the right and left as distinguished from the upper and lower) are sensitive to their changed relation to gravity (on account of the new horizontal posi- tion), which thus becomes a stimulus. The re- sponse of the stem to this stimulus is an accel- erated growth on one Hank, the right or left, as the case may be. The acceleration of growth there swings the horizontal tip toward a new point of the compass, and at the same time, from mechanical necessity, partially rotates the stem on its longitudinal axis, so that a new side is brouglit into the Hank position and therefore under stimulation. It then responds likewise with accelerated growth; this swings the tip still farther around, and again brings a new region under stinuilation. By this continued action each side of the stem is successively stimulated, and the tip is therefore swung in a circle. At the same time it is elongating. If, in the course of its twining, the nearly horizontal tip strikes a support, only the part "lx?yond the support con- tinues to swing, and therefore begins to wrap around the support, forming coils which are at first low and loose. At a later period negative geotropism again asserts itself in this part of the stem, which grows so that it straightens, if possible, the actual effect being to steepen the coils and make them hug the support more close- ly. The slenderer the support, as a rule, the steeper are the completed coils. This explana- tion receives its strongest support from the fact that when the action of gravity is equalized, as it can be by rotating a seedling twiner on a clin- ostat (q.v.), no coiling takes place. There are various phenomena of twining, experimentally in- duced, of which no full explanation can yet be given. There is, however, no mere meclianical stoppage of the swinging tip which permits coil- ing, because it has no momentum, and because many twiners will coil about a loose cord. It is further proljable that twiners are susceptible to the continued contact and pressure of the sup- port, and that this plays some part in the method of climbing which they have adopted. Twining plants are characterized by unusual- ly long growing regions, and by the retarded de- velopment of foliage leaves. Thus, while in erect stems from 10 to 20 centimeters (4 to 8 inches) of the apex are still capable of elongation, in twining plants the elongating region is 30 to 50 centimeters (12-20 inches) long, or in some cases as much as 80 centimeters (32 inches). The slow development of the foliage leaves seems both to be correlated with this long maintenance of the power of growth, and to be necessary for twin- ing, because the presence of fully developed foli- age would interfere seriously with the free move- ments of the tip. TWISS, Sir Tr.wers (1809-97). An Engli.sh jurist and scholar. He was born in Marylebone, London, graduated from University College. 0.x- ford, with distinction, and published in 1836 his Epitome of Xiebiilii's I{i.<itorji nf Rome. In 1840 he was called to the bar. From 1842 to 1847 he was professor of political economy at Oxford, from 1852 to 1855 professor of international law at King's College, London, and from 1855 to 1870 held the regius professorship of civil law at Ox- ford. He also held several ecclesiastico- legal po- sitions, and in 1858 became chancellor of the dio- cese of London, the same year having been created