Page:The New International Encyclopædia 1st ed. v. 14.djvu/816

* NUTATION. 694 NUTHATCH. NUTATION (in Plants). The bending raove- nifiils exei/uled by organs of plants, such as stems, leaves, roots, etc., by which the part is inclined successively in various directions. Nutations are due to the unequal rate of growth of dili'erent sides of the organ, an ineijuality which, as far as is known at present, is de- pendent upon internal (unknown) causes, and is not called forth by the action of external stimuli. See InRiTABiLiTY. Simple nutation occurs in dorsiventral organs, such as flat leaves, both foliage and tloral. The movements are only in one plane, being dependent upon the unci|iial growth of the opposite sides. When young the growtli of the foliage leaves is most rapid upon their outer (dorsal) face, in consequence of which the leaf applies itself to the axis, arches over the apex, and with its neigli- bers forms a compact bud. Later, growth be conies more rapid on the inner (ventral) face, the bud opens, and the leaves straighten out. Similar inequality of growth, but more sliarply localized, leads to the folding and rolling of the leaf in the bud. (See Vernation, under Bub. ) Like movements of radial organs, such IftJTATION OF THE TIP OF THE PEA-STEM. The dotH reprt'Hent tin- oliHi-rvatloiie ; the line Ip drawD merely to show their wriai reintion. doubtleflfi lens uuKiilur. 'i'iie true path le as stems, cylindrical leaves, and roots, have been termed circumnutation or revolving nutation, to distinguish them from the simple nutation of dorsiventral organs. When any plant is in vigorous growth the axis rarely grows in length uniformly on all sides. The side on which growth is most rapid will ))ush the apex over toward the side on which growtli is less rapid. If the region of more rapid growth changes, shifting around the a.is, the tip will be inclined successively to all points of the compass, and with its simul- taneous upward growth will describe a spiral; but since the rate of growth is not uniform at 6iicce.s.sive intervals, the path described will be a very irregtilar spiral. A path of this kind, re- diieed to a plane, is shown in the accompanying figure. Movements quite similar to those above de- scribed are called forth in plant organs as re- sponses to external stimuli. Thus twining plants exhibit both true nutation and nutation due to a geotropic sensitiveness. (8cc LiKOTKOi'l.sM I.x 1'lant.s.) Changes in temperature cause flowers to open or close by movements which resemble the simple nutation of dorsiventral organs. Thus the tulip, crocus, and other vernal llowers are very .sensitive to changes in temperature. The latter can perceive a cliange of 0.5" C, and will respond to a cluuige of 2U° C in two minutes. NUT-BROWN MAID, The. An English ballad of the tiflccnlli ceiituiy, telling the ex- ic|ilional story of tlic maid, a high-born lady, who maintains her love and constancy to her outlaw lover through the tests he uses to try lier. Finally she conquers, and finds the outlaw is also of higli degree, and his banishment is feigned. The lover has been supposed to be the Karl of Cumberland, and the nut-brown maid, -Margaret Percy. The earliest version is found in Arnold's "(Chronicle," a collection of London antiquities (1502). it was reprinted in 1707 in the "iluscs" Mercury," and paraphrased by I'rior in his "Henry and Emma," in 1718. NUT-CBACKEB. A bird of the crow family, of the genera Xiuifraga and Picicorvus. The form and characters are similar to those of crows, but the habits are rather those of jays, and in some respects indicate an ap])roach to woodpeckers. One species {yucifraya rari/o- calav.tcs) is not unconinion in Europe and Asia, particularly in numntainous regions covered with pines. It is about the size of a jay. but has a longer tail. The plumage is light brown, speckled with white, except on the wings, rump, and tail, which are nearly black. The nut- cracker frequents the tops of high i)iiies. is shy, and breeds earlier than most birds, and in a very secretive manner. Its food, a|>art from some in- sects in summer, consists of the seeds extracted from pine cones. These it holds with its feet while it works at them; but its ability to crack a nut, in spite of its name, is doubtful. The only American nut-cracker { ricicornis Voliim- l)i(inus), usually called "Clarke's crow,' inliabits the pine regions of the West from Mexico to .laska. and is gray with black and white wings and tail. It is noisy and gregarious, but during the breeding sea.son it is shy. It builds its nest in the tops of tall pines and conceals it with care. The eggs are liglit grayish green, marked with grayish brown and lilac. Consult: Newton. Die- lUinari) of Birds (London. 18n.'i-9U) : Coues, llirds'of the yorllni^st (Washington. 1874); Keyser, Birds of the h'orl:i(S (New York. 1902). See Plate of Jays. Maiumes. etc.: and Colored Plate of Er.cs ov So.Nu UlHU.S. NUTGALL, or Gall. See Gall-Ixsbcts. NUT GRASS. See Chufa, and Plate of Ct- riii:ss. i;i(. NUTHATCH (formerly also xiilhnck. MK. nulhnkc, nutlili<il;i, from init + Imck). A genus of liirds of (lie family Parida', having a straight bill and short legs, the hind toe very strong. The genus is represented in North .America hv four species, of which the white-bellied nuthatch (flilla Carolinriisis) is the commonest and best known. It is found throughout the whole United States and Canada, and is about six inches long, ilear ashy blue above, white beneath, and wilh the crown rich, glossy, green-black. It is abun- dant in most localities in the fall and spring and