In 6 cotilidon. [a. L. cotylēdon the plant navelwort or pennywort, a. Gr. κοτυληδών (f. κοτύλη: see prec.) a cup-shaped cavity, the sucker of an octopus, also in senses 1, 2 below. Sense 1 was used in Fr. by Paré (16th c.). The botanical sense 3 was introduced (in mod.L.) by Linnæus.]
1. Phys. One of the separate patches of villi on the fœtal chorion of Ruminants; also applied to the corresponding vascular portions of the uterine mucous membrane.
Formerly applied also to the less separated lobules of the human and other discoid or diffuse placentæ.
1545. Raynold, Byrth Mankynde, II. vii. (1643), 132. Cotilidons, that is, the veynes by the which the conception and feature is tyed and fastened in the Matrix.
1634. T. Johnson, trans. Parey’s Chirurg., III. xxiii. (1678), 85. The Cotyledones [of the Uterus] … are nothing else than the orifices and mouths of the Veins ending in that place.
1684. trans. Bonet’s Merc. Compit., XIV. 513. Cassia … relaxeth the Womb, and weakens the Cotyledons.
1787. Hunter, in Phil. Trans., LXXVII. 444. Without any small protuberances for the cotyledons to form upon, as in those of ruminating animals.
1869. Huxley, Introd. Classif. Anim. 97. A fœtal cotyledon … half separated from the maternal cotyledon … of a Cow.
2. Bot. A genus of plants of the N.O. Crassulaceæ, having thick succulent peltate leaves; the British species is C. Umbilicus, popularly called Navelwort or Pennywort.
1601. Holland, Pliny, II. 237. Cotyledon, named in Latine Vmbilicus Veneris, is a pretty little herb, hauing … a leafe thick and fatty, growing hollow, like to the concauity wherin the huckle-bone turneth, and therupon it took the foresaid name in Greek.
1741. Compl. Fam. Piece, II. iii. 404. We have now … Cotyledons, Chrysanthemums.
1861. Miss Pratt, Flower. Pl., II. 319. Cotyledon (Penny-wort).
3. Bot. The primary leaf in the embryo of the higher plants (Phanerogams); the seed-leaf.
The number of cotyledons in the seed serves as an important basis of classification of Angiosperms into MONOCOTYLEDONS (= ENDOGENS) with one cotyledon, and DICOTYLEDONS (= EXOGENS) with two; in Gymnosperms the number varies, being usually more than two.
[The term was introduced by Linnæus, and was esp. applied by him to those seed-leaves which are not themselves depositaries of nutriment, but act as organs of absorption, in which he saw an analogy to the function of the cotyledons of the placenta (sense 1). Cf. Gaertner, De Fructibus (1788), clxii.]
[1751. Linnæus, Philos. Bot., 54. Cotyledon, corpus laterale seminis, bibulum, caducum. Ibid., 89. Cotyledones animalium proveniunt e Vitello ovi, cui punctum vitæ innascitur; ergo Folia seminalia plantarum, quæ Corculum involverunt, iidem sunt.]
1776. J. Lee, Introd. Bot. (ed. 3), 410. The Seeds have two Cotyledons.
1845. Lindley, Sch. Bot., i. (1858), 18. The embryo consists of three parts, the radicle, or young root, the cotyledons, or young leaves, and the plumule, or young stem.
1875. Bennett & Dyer, trans. Sachs’ Bot., II. v. 443. In some Cupressineæ there are from three to nine, and in some Araucarieæ whorls of four cotyledons; while among the Abietineæ there are … four or even as many as fifteen.
