Pl. vela. [L. vēlum a sail, awning, curtain, covering, veil.]
1. † a. A screen or protection. Obs.
1781. Priestley, in Young, Autobiogr. (1898), v. 99. A glass velum, interposed between the retort and the recipient for the air, remains quite cool and dry.
b. A velarium.
1843. Penny Cycl., XXVI. 197/2. Such ceiling or vault therefore assumes somewhat the appearance of an awning or velum stretched immediately upon arches.
2. Anat. a. The soft palale; the membranous septum extending backwards from the hard palate.
Also more fully velum palati and velum pendulum.
(a) 1771. Encycl. Brit., I. 303/1. The septum, which may likewise be termed velum, or valvula palati, terminates below by a loose floating edge.
1782. Heberden, Comment., vii. (1806), 27. The velum pendulum was putrid.
1805. Med. Jrnl., XIV. 179. One was removed … from behind the velum pendulum by the forceps.
1847. Todd’s Cycl. Anat., III. 951. The velum palati is a soft moveable curtain stretching backwards and downwards into the cavity of the pharynx [etc.]. Ibid. Muscles of the velum palati.
1859. Semple, Diphtheria, 55. The posterior column of the velum palati.
(b) 1753. Dict. Arts & Sci., III. 2313/2. The great uses of this membrane are … for preventing by its claustrum or velum, the things to be swallowed from getting up into the nostrils.
1826. S. Cooper, First Lines Surgery, 241. The velum and uvula are occasionally destroyed.
1846. Brittan, trans. Malgaigne’s Man. Oper. Surg., 365. You see then the importance of passing the needles through a well determined point of the velum.
1879. St. George’s Hosp. Rep., IX. 725. A child … was attacked by sore-throat with false membrane, which spread from the tonsils over the velum.
attrib. 1879. St. George’s Hosp. Rep., IX. 570. Voice husky; glands of velum palate enlarged.
b. One or other of two membranes extending from the vermiform process of the brain.
1840. G. V. Ellis, Anat., 52. The two medullary vela are inclined obliquely towards each other. Ibid. The anterior medullary velum or valve of Vieussens.
1873. Mivart, Elem. Anat., 377. The velum consists only of the ependyma, the pia mater, and the arachnoid.
c. A triangular fold of the pia mater lying between the third ventricle and the fornix of the brain. (In full velum interpositum.)
c. 1845. Todd’s Cycl. Anat., III. 635. The velum interpositum is best exposed … by removing carefully in succession the corpus callosum and the fornix. In raising the velum itself [etc.].
d. A small triangular space in the inferior region of the bladder.
1835–6. Todd’s Cycl. Anat., I. 385/1. This membrane presents some peculiarities throughout the extent of a small region named the ‘trigone’ or the ‘velum’ of the bladder.
3. Zool. A membrane or membranous integument, esp. one occurring in mollusks, medusæ or lower forms of animal life.
1826. Kirby & Sp., Entomol., III. 370. Velum (the Velum), a membrane attached to the inner side of the cubital spur in Apis.
1840. Penny Cycl., XVI. 110/1. Though the term velum is used, which would hardly be applicable to the palmated arms or vela of the other kind [of Nautilus].
1877. Huxley, Anat. Inv. Anim., iii. 129. The inner margin of the bell in these medusoids is always produced into a velum.
1887. Encycl. Brit., XXII. 420/1. In the majority of sponges both excurrent and incurrent canals are constricted at intervals by transverse diaphragms or vela, which contain myocytes concentrically and sometimes radiately arranged.
4. Bot. A membranous structure or covering in certain fungi.
1832. Lindley, Introd. Bot., 208. The velum, or veil, is a horizontal membrane, connecting the margin of the pileus with the stipes.
1866. Treas. Bot., 1207/1. Velum, the annulus of certain fungals.
1882. Vines, trans. Sachs’s Bot., 337. This formation of a velum is connected with the entire growth of the whole fructification.
