corn drill (korndril)

A machine for sowing corn in drills. cornea (kôr'nē-a), n. [NL., fem. of L. corneus, horny: see corneous.] 1. The firm, transparent anterior portion of the eyeball. It is of circular outline, concavo-convex, with the convexity for ward, bounding the anterior chamber of the eye in front, by its margin continuous with the sclerotic, and having its outer surface, as a rule, covered with a delicate layer of the conjunctiva. In the human eye it forms about one sixth of the entire eyeball. Its convexity is greater than that of the sclerotic, forming a comparatively larger portion of a smaller sphere than the The cornea is so called from its hardne , being likened to horn; it is also known as the tunica cornea pellucid a or pellucid horny 1269 coat of the eye, in distinction from the sclerotic. See cut under eye. 2. In entom., the outer surface of an insect's compound eye. It is generally smooth, but may be hairy. The word is also used to designate the outer transparent lens of each facet of a compound eye, and the surface of an ocellus or simple eye. See cornea-lens. Absci ion of the cornea. See absci ion. corneal (kôr'nē-al), a. [ The corneal surface of the eye is transversely elongated and reniform, and its pigment is black. Huxley , Crayfish, p. 237. Bowman's corneal tubes, the tubular pa ages formed in the fibrous layers of the cornea by forcible injection. cornea-lens (kôr'nē-ä-lenz), n. A facet of the cuticular layer of the compound eye of an arthropod; the superficies of an ocellus; a corneule. Faceted cuticular layer, each facet of which forms a cor nea-lens. Gegenbaur , Comp. Anat. (trans.), p. 266.