| 释义 |
‖ ovum|ˈəʊvəm|
Pl. ova (erron. 8 ovas, 8–9 ovæ).
[L. ōvum egg.]
1. Biol.
a. Zool. The female germ or reproductive cell in animals, produced (usually) by an ovary, and capable when fertilized or impregnated by the male sperm (and in some cases without such fertilization) of developing into a new individual; an egg in the widest sense, including the eggs of birds (the largest of all animal cells), but more commonly applied to the extremely small germs of female mammals, or to the eggs of oviparous animals when of small size, as in fishes, insects, etc.
1706Phillips, Ovum, an Egg; also the Spawn of Fish. 1722De Foe Plague (1884) 102 Poisonous Ovæ, or Eggs, which mingle themselves with the Blood. 1784Twamley Dairying 129 By burning the Moss, you destroy at the same time, the Ovas or Eggs, the Chrysalis and grubs. 1797M. Baillie Morb. Anat. (1807) 403 This arises from the ovum being stopped in its progress from the ovarium to the uterus. 1861J. R. Greene Man. Anim. Kingd., Cœlent. 14 True reproduction, by contact of ova and spermatozoa. 1879Cassell's Techn. Educ. IV. 154/1 The number of germs or ova brought forth by a single mature oyster exceeds one million. 1889Geddes & Thomson Evol. Sex xiii. 169 What we now mean by parthenogenesis, or the development of ova without union with sperms.
†b. Bot. The ovule or seed of a plant. rare.
1760J. Lee Introd. Bot. ii. xx. (1765) 119 When the Ova are hatched, the Cotyledons preserve the Form of the halved Seed. 1866Treas. Bot., Ovule, Ovum, the young seed.
2. Arch. An egg-shaped ornament or carving.
1727–41Chambers Cycl., Ova, in architecture, are ornaments in form of eggs, carved on the contour of the ovolo, or quarter-round; and separated from each other by anchors, or arrows heads. 1823P. Nicholson Pract. Build. Gloss. 589/1 Ova, an ornament in form of an egg. 1851E. J. Millington tr. Didron's Chr. Iconogr. 316 Immediately below the ovæ of the cornice.
3. attrib. and Comb., as ovum-cycle, ovum-product; often with the pl., as ova-bearing, ova-containing adjs., † ova-duct (= oviduct), ova-hatching.
1781Smeathman in Phil. Trans. LXXI. 172 note, Two ovaria, in each of which are many hundred ova-ducts. 1846Dana Zooph. v. §85 (1848) 87 The distinction in plants of budding and ova-bearing individuals. 1883P. Geddes in Encycl. Brit. XVI. 843/2 The genealogical individual of Gallesio and Huxley..may be designated with Haeckel the ovum-product or ovum-cycle. 1898P. Manson Trop. Diseases 414 Because leprosy is common in the descendants and blood collaterals of lepers, this is no proof of ovum infection. |