HORMOGONIUM
Hor`mo*go*ni"um, n. Etym: [NL., fr. Gr. (Bot.)
Defn: A chain of small cells in certain algæ, by which the plant is propogated.
HORMONE
Hor"mone (hôr"mon), n. [From Gr. "orma`ein to excite.] (Physiol.
Chem.)
Defn: A chemical substance formed in one organ and carried in the circulation to another organ on which it exerts a stimulating effect; thus, according to Starling, the gastric glands are stimulated by a hormone from the pyloric mucous membrane.
HORN
Horn, n. Etym: [AS. horn; akin to D. horen, hoorn, G., Icel., Sw., &
Dan. horn, Goth. haúrn, W., Gael., & Ir. corn, L. cornu, Gr. cheer,
cranium, cerebral; cf. Skr. çiras head. Cf. Carat, Corn on the foot,
Cornea, Corner, Cornet, Cornucopia, Hart.]
1. A hard, projecting, and usually pointed organ, growing upon the heads of certain animals, esp. of the ruminants, as cattle, goats, and the like. The hollow horns of the Ox family consist externally of true horn, and are never shed.
2. The antler of a deer, which is of bone throughout, and annually shed and renewed.
3. (Zoöl.)
Defn: Any natural projection or excrescence from an animal, resembling or thought to resemble a horn in substance or form; esp.: (a) A projection from the beak of a bird, as in the hornbill. (b) A tuft of feathers on the head of a bird, as in the horned owl. (c) A hornlike projection from the head or thorax of an insect, or the head of a reptile, or fish. (d) A sharp spine in front of the fins of a fish, as in the horned pout.
4. (Bot.)