‖ hilum
(ˈhaɪləm)
[L. hīlum little thing, trifle; according to Festus, thought to have orig. meant ‘that which adheres to a bean’; hence in mod. Bot. use (see 2).]
† 1. Something very minute. Obs.
| 1659 D. Pell Impr. Sea 44 Unhewn Sailors, that have no more than a meer hilum of goodness in them. |
2. Bot. The point of attachment of a seed to its seed-vessel; the scar on the ripe seed.
| 1753 Chambers Cycl. Supp., Hilum, a word used by botanists to express the blackish spot in beans, commonly called by us the eye of the bean. 1830 Lindley Nat. Syst. Bot. 115 Seeds..with a smooth shining coat, and a broad pale hilum. 1880 Gray Struct. Bot. vi. §8. 277 In the simplest form of ovule, hilum and chalaza are one. |
b. A similar mark on a starch-granule. c. ‘The aperture in the extine of a pollen grain’ (Syd. Soc. Lex.).
| 1867 J. Hogg Microsc. ii. i. 341 Most of the granules [of starch] have a circular spot, termed the hilum, around which a large number of curved lines arrange themselves. |
3. a. Anat. = hilus. ‘Applied also to certain small apertures and depressions’ (Syd. Soc. Lex.).
b. Path. ‘A term for a small flattened staphyloma of the iris from corneal perforation, in consequence of its likeness to the hilum of the garden bean’ (Syd. Soc. Lex.).
c. A little opening in the statoblast of a sponge.
| 1887 Sollas in Encycl. Brit. XXII. 424 (Sponges) On one side of the capsule is a hilum which leads into the interior. |