| 释义 |
‖ jugum Bot.|ˈdʒuːgəm|
Pl. juga.
[L. jugum yoke.]
1. a. A pair of leaflets in a pinnate leaf. b. Each of the ridges on the carpels of Umbelliferæ.
1857Henfrey Elem. Bot. 59 The pairs of leaflets [in pinnate leaves] are sometimes called juga, and if only one pair exists, the leaf is unijugate. 1880Gray Struct. Bot. (ed. 6) 417/2 The ridges in the fruit of Umbelliferae are termed juga.
2. a. Zool. In certain brachiopods with hinged shells, a process of the dorsal valve. b. Ent. In certain Lepidoptera, a lobe on the fore wing which is able to link it to the hind wing. Hence ˈjugal, ˈjugate adjs.
1888Rolleston & Jackson Forms Animal Life (ed. 2) 693 One valve may have depression or sinuses to which correspond elevations or juga on the other. 1893J. H. Comstock in Wilder Quarter-Century Bk. 43 There are two distinct ways of uniting the two wings of each side in the Lepidoptera; they may be united by a frenulum or..by a jugum. Ibid. 84 In this genus [sc. Hepialis]..they [sc. the wings] are joined by a membranous lobe extending back from near the base of the inner margin of the fore wing. To this lobe I have applied the name jugum. 1895J. H. & A. Comstock Man. Study Insects xviii. 215 This projecting lobe is named the jugum or yoke; and the moths possessing this organ are termed the Jugatæ or the Jugate Lepidoptera. 1952R. C. Moore et al. Invertebr. Fossils vi. 213/1 A variously shaped crossbar between the spiralia is called [the] jugum; it has considerable importance in classifying some groups of spine-bearing brachiopods. 1957Richards & Davies Imms's Gen. Textbk. Ent. (ed. 9) 538 Wing-coupling apparatus of jugate type, the jugal lobe elongate and resting upon the hind wing. 1969R. F. Chapman Insects x. 175 The Hepialidae have a strong jugal lobe which lies beneath the costal margin of the hind wing so that this is held between the jugum and the rest of the fore wing.
Restrict Bot. to sense 1 and add: 3. Anat. A ridge or furrow connecting certain structures, esp. on bone. Chiefly in specific applications with (modern) Latin epithet, as juga alveolaria, jugum sphenoidale, etc.
1887L. Heitzmann tr. C. Heitzmann's Anat. i. 23 Right superior maxillary bone... The alveolar process contains 8 alveoli for the reception of the teeth; its outer plate shows eminences, Juga alveolaria. 1893J. B. Sutton in H. Morris Treat. Human Anat. i. 37 In the course of the first year the orbito-sphenoids fuse in the middle line to form the jugum sphenoidale, which excludes the anterior part of the pre-sphenoid from the cranial cavity. 1962Gray's Anat. (ed. 33) 314 Anteriorly the jugum articulates with the posterior margin of the cribriform plate. |