| 释义 |
scutellum|skjuːˈtɛləm|
Pl. scutella.
[mod.L.; app. in origin a supposed correction of scutella (see scutella), due to the notion that this was a dim. of L. scūtum shield; the applications are based on the rendering ‘little shield’.
The correct L. dim. of scūtum was scūtulum, which some mod. scientific writers have adopted as a basis for derivatives, using, e.g., scutulate instead of scutellate.]
1. Bot.
a. (See quots.)
1760Lee Introd. Bot. iii. xxii. (1765) 227 Scutellum, a small Buckler, which is a concave orbiculate Fructification, the Margin of which is elevated on every Side. 1793Martyn Lang. Bot., Scutellum... An orbicular concave fructification (in some Lichens). 1866in Treas. Bot.
b. An anterior cotyledon in certain grasses.
1832Lindley Introd. Bot. i. ii. 191 In wheat there is a second small cotyledon on the outside of the embryo, inserted a little lower down than the scutelliform cotyledon. This last is called scutellum by Gærtner, who considered it of the nature of vitellus. 1880Bessey Bot. 451 The first leaf of the young plant (the cotyledon or scutellum). 1882Vines tr. Sach's Bot. 620 In Grasses, however, the whole of the plumule projects from the seed, the scutellum only remaining behind in it.
c. (See quot.)
1900B. D. Jackson Gloss. Bot. Terms, Scutellum..the conical cap of the endosperm in Cycadeae.
2. Zool.
a. Ent. The third of the four sclerites composing any segment of the tergum of an insect; usually, the mesoscutellum.
1819G. Samouelle Entomol. Compend. 266 Two stripes near the scutellum. 1896tr. Boas' Zool. 259 A triangular median portion of the mesothorax (scutellum) remains uncovered.
b. Ornith. One of the horny plates which cover the feet of certain birds.
1840Macgillivray Man. Brit. Ornith. I. 64 Toes short, feathered, all with two scutella at the end. 1884Coues Key N. Amer. Birds (ed. 2) 249 Mimus...Tarsal scutella always distinct. |