单词 | diatom |
释义 | diatomn. A member of the genus Diatoma, or, in a wider sense, of the Diatomaceæ, an order of microscopic unicellular Algæ, with silicified cell-walls, and the power of locomotion, on which account they were formerly placed by many naturalists in the Animal kingdom. They exist in immense numbers at the bottom of the sea, as well as in fresh water; and their siliceous remains form extensive fossil deposits in many localities. The genus Diatoma is distinguished by having the frustules, or individual cells, connected by their alternate angles so as to form a kind of zig-zag chain: hence the name. ΘΚΠ the world > plants > particular plants > algae > [noun] > diatom(s) diatom1845 brittlewort1846 diatomean1853 1845 Gray Lett. (1893) 332 Then the low, minute forms and Confervæ come..ending with diatoms, transitions to corallines through sponge, etc. 1853 W. Smith Brit. Diatomaceæ 25 During the healthy life of the Diatom the process of self-division is being continually repeated. 1858 C. P. Smyth Astron. Exper. Peak of Teneriffe 6 The countless millions of diatomes that go to make a feast for the medusæ. 1863 J. D. Dana Man. Geol. §74 Microscopic siliceous shields of the infusoria called diatoms, which are now regarded as plants. 1865 P. H. Gosse Land & Sea (1874) 158 The name Diatoma..has reference to the readiness with which the strings or chains in which most of the forms are aggregated may be separated.] 1882 S. H. Vines tr. J. von Sachs Text-bk. Bot. (ed. 2) 260 The movements of Diatoms are not altogether dissimilar to those of Desmids, and even the silicification of the cell-wall..is found, though to a smaller extent, in Closterium and other Desmids. This entry has not yet been fully updated (first published 1895; most recently modified version published online March 2022). < n.1845 |
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