| 释义 |
polyembryonate, a. Bot.|pɒlɪˈɛmbrɪənət|
[f. poly- + embryon + -ate1.]
Containing more than one embryo, as a seed. So polyembryˈonic a. = prec.; also, pertaining to polyembryony. polyˈembryony, the formation or presence of more than one embryo in a seed; also Zool., the development of more than one embryo from a single egg.
1849Balfour Man. Bot. §509 Cases of polyembryony in Coniferæ, Cycadaceæ, Mistleto, Onion, &c. Ibid. §586 In Coniferæ, Cycadaceæ, Mistleto, &c., there are frequently several embryos, giving rise to what is called polyembryony. 1864Webster, Polyembryonate..Polyembryonic. 1906Science 21 Dec. 813/2 Polyembryony [in Encyrtus eggs] reaches its greatest intensity..when the young larvæ of the Hyponomeuta leave their winter shelter. 1912Anatomischer Anzeiger XLI. 369 (heading) The demonstration of polyembryonic development in the armadillo. 1925A. D. Imms Gen. Textbk. Entomol. i. 154 Polyembryony is met with among insects in certain parasitic families of Hymenoptera. 1947Arch. Path. XLIV. 501 There has been much speculation concerning the cause of polyembryony (monozygotic multiple birth) as it occurs regularly in the armadillo. 1956Nature 28 Jan. 191/1 An examination of the seeds of different species of Cassia..has shown the occurrence of polyembryony to be geographically widespread. 1969R. F. Chapman Insects xix. 377 The effect of polyembryony is to increase the reproductive potential of the insect, but the net effect is not always much greater than in related monoembryonic species because polyembryonic forms tend to lay fewer eggs. |