| 释义 |
metachronism|mɛˈtækrənɪz(ə)m|
[ad. med.L. metachronism-us, a. late Gr. type *µεταχρονισµός, f. µετα- meta- + χρόνος time. Cf. F. métachronisme.
Normally the word should mean ‘transposition of dates’ (cf. quot. 1656 below); but it has been associated with Gr. µετάχρονος, µεταχρόνιος happening later, f. µετά after + χρόνος time; hence the sense explained below, which seems to be that of all the available instances.]
1. An error in chronology consisting in placing an event later than its real date. (Cf. parachronism.)
1617Hales Serm. 36 There are in Scripture..anachronismes, metachronismes, and the like, which bring infinite obscuritie to the text. 1656Blount Glossogr., Metachronism, an error in the connexion of things or times, by reckoning or accounting short or beyond the truth. 1677R. Cary Chronology ii. i. i. xx. 157 Our Authour..is..guilty of a foul Metachronysm, in accomodating the 5th of Cambyses to his 4986 of the World.
2. Biol. The co-ordination of the movement of parts, esp. cilia, into a progressive wave.
1905Jrnl. Exper. Zool. II. 408 It is the principal object of this paper to discuss the cause of metachronism in ciliary action. 1928J. Gray Ciliary Movement vii. 117 Any particular cilium is slightly in advance of the cilium behind it in the series and slightly behind the one just in front of it. This regular sequence is known as metachronism. 1972M. S. Gardiner Biol. Invertebr. iv. xi. 189/1 In Metazoa, the cilia on adjacent cells may exhibit a similar coordination in metachronism.
So metaˈchronal a., exhibiting or characteristic of metachronism (sense 2); metaˈchronally adv.
1905Jrnl. Exper. Zool. II. 407 The cause of metachronal action is..to be sought..in the mechanical effect of one cilium on another. Ibid., These swimming plates are arranged in rows and the members of each row, like ordinary cilia, beat metachronally, not synchronally. 1928J. Gray Ciliary Movement vii. 118 Although the direction of the metachronal wave..differs in different tissues, it is remarkably constant in each particular case. 1940G. S. Carter Gen. Zool. Invertebr. viii. 359 Metachronal rhythm is not confined to metazoan cilia; it can be well seen in such ciliate protistans as Opalina. 1962D. Nichols Echinoderms viii. 99 In at least one urchin, Diadema, the spines show metachronal rhythm during locomotion, and they move the animal across the ocean floor with considerable speed. 1971Nature 12 Feb. 491/1 The cilia of these last two cell types beat metachronally. |