amnicoloid (amnikoloid)

[ amnion (amni-on), n.; pl. amnia (-a). [NL Gr. ἀμνίον, the membrane around the fetus (also called ἀμνεῖος χιτών ), also the bowl in which the blood of victims was caught at the sacrifices; envelop the embryo of the higher vertebrates, as mammals, birds, and reptiles; the lining membrane of a shut sac, familiarly called the "bag of waters," in which the fetus is contained. An amnion is developed in those vertebrates only which have a fully formed allantois; hence it is absent in the Ichthyopsid a , or fishes and amphibians, but present in all The amnion is formed, at a very early period amaie of the embryo, by a duplication of the epiblast, or external blastodermic membrane, which, carrying with it a layer Sauropsida, or reptiles and birds, and in Mammal i a . of mesoblast from the somatopleural division of the latter, rises on all sides about the embryo, the folded edges coming together over the back of the embryo, and there coalescing to form a shut sac in which the embryo is inclosed. From this mode of growth, it is obvious that what was the outer side of the amniotic folds becomes the inner side of the sac when it has shut, so that the epiblastic layer is internal, the mesoblastic external; the proce of inversion being comparable to that by which, in the case of the primitive trace of the embryo, a layer of epiblast is con verted into the lining of the spinal canal. Only that fold of membrane which is next the body of the embryo com IMG:content-0632.png:[blocks in formation] poses the amnion proper, the other or outer fold in contact with the enveloping primitive chorion (vitelline membrane or yolk-sac) either disappearing or taking part in the formation of the permanent chorion. As long as this outer fold is recognizable as a membrane, it bears the name of false am nion. The shut sac of Am the amnion contains the liquor amnii, a bland, albuminous, serous fluid in which the fetus is immersed. In parturition, rupture of the sac is followed by the "bursting of the waters." Sometimes a portion of the sac adheres to the head of the child, fitting like a skull-cap; such an infant is said, in the language of midwives, who commonly regard the circumstance as a good omen, to be "born with IMG:content-0633.png:[graphic] Vertebrate Embryo (chick, 5th day of incubation), showing Am , the inclosing amnion; n, o, rudiments of anterior and posterior limbs, or limb-buds; 1, 2, 3, first, second, and third cerebral vesicles; ra , vesicle of the third ven tricle; h, eye; k, visceral arches and clefts; All , allantois, hanging by its pedicle; Um , portion of umbilical vesicle. a caul." Those verte IMG:content-0634.png:[blocks in formation] Amebæa (am-e-bēi), n. pl . [NL., neut. pl. of L. amabæus , alternate: see amabean1 .] The name given by Ehrenberg to the amœbiform organisms which he placed in his Poly gastric a . amole (a-mō'le), n. [Mex.] 1. A Mexican name amabæum (am-e-bē'um), n.; pl. amabæa (-a). [L., neut. of amabæus, άμοιβαῖος , recipro- cal, alternate, άμοιβή , change, alternation: see amaba .] A poem in which persons are repre- sented as speaking alternately, as in the third and seventh eclogues of Virgil. ameba-movement (a-mē'ba-möv"ment), n. A movement of naked membrane le protoplasmic bodies, consisting of rapid changes in external contour, extension and contraction, and a creep- IMG:content-0635.png:[blocks in formation] amnionic (am-ni-on'ik), a. [The proper form would be *amniac; amnion ( amni -on) + (-ac).] Of, pertaining to, or of the nature of an amnion; amniotic. IMG:content-0636.png:[blocks in formation] amock, a. or adv . See amuck . ameba (a-mē'ba), n.; pl. amabas, amabæ (-baz, -bē). [NL., E. move, q. v.] 1. [ cap .] A ge- nus of microscopic rhizopodous Protozoa , of which A. diffluens , common in all fresh-water ponds and ditches, is the type. It exists as a ma of protoplasm, and moves about and grasps particles of food, etc., by means of pseudopodia, or finger-like pro- ce es, which it forms by protruding portions of its body. From thus continually altering its shape it received its for mer name of proteus animalcule . Within the body are usually found a nucleus and nucleolus, and certain clear spaces, termed contractile vesicles, from their exhibiting rhythmical movements of contraction and dilatation. There is no distinct mouth, and food seized by means of the pseudopodia is engulfed within the soft sarcode-body and by any portion of its surface, the apertures by which the food is taken in closing up im- mediately after its re- ception. Reproduction takes place in several ways, but chiefly by fis- sion, whereby an amœba simply divides into two portions, each of which becomes a distinct ani- malcule. Several other ameban (a-mē'ban), a. Of or pertaining to the amœbas; amœbous. Amœbea (am-e-bē'ä), n . pl . [NL., Amaba , q. v.] An order of Rhizopod a , of which the genus Amaba is the type. See Amaba . amœbean1 (am-ē-bē'an), a . [L. amabæus , amabæum .] Alternately answer- bæum (which see). Also spelled amebean . ing or responsive; of the nature of an ame- plants which furnish these roots. In New Mexico and adjacent parts of Mexico the most common species is the lechuguilla, Agave heteracantha . In California the name is given especially to Chlorogalum pomeridianum, a liliaceous plant having large bulbs coated with coarse brown fibers, of which mattre es are made. See soap - plant . amolisht, v. t. [ amoli - , stem of certain parts of amolir , amoliri , remove with an effort, ab , away, + moliri , exert one's self upon, move, moles , a heavy ma : see moles. Cf. demolish .] To remove forcibly; put away with an effort. [Rare.] amolitiont, n. [L. amolitio( n- ), amoliri , pp. amolitus , remove: see amolish .] A putting away; removal. [Rare.] amollisht, v . t . [ME. amoli hen, amo- li - , stem of certain parts of amolir , F. amol- lir , soften, ad , to) + molir , moll is , soft: see moll , mollify .] To soften; mollify; mitigate. a moll ish ment (a-mol'ish-ment), n. [Also writ- ten amolishment , amolli ement : see amol- lish and -ment .] Softening; mitigation. Donne . (N. E. D.) Amœbidæ (a-me'bi-dē), n . pl . [NL., Ameba + -ida .] The typical family of the Amaba , Amabina , or Amaboidea , mainly represented by the genus Amaba , as distinguished from such amœboids as are members of Difflugia and Arcella , or such other rhizopods as the sun-ani- malcules, as Actinophrys sol , etc. amœbiform (a-me'bi-form), a . and n. [ -form .] I. a. Ameba-like; undergoing frequent changes of shape, like an amœba; re- IMG:content-0637.png:[blocks in formation] II. n. An amœba, or an animal or corpuscle of ameban character. See amœba , 3. Other genera of the amœbiforms . Amebina (am-e-bi'nä), n . pl. [NL., -ina .] See Amœboidea . amœbodont (a-mē'bo-dont), α. [ ὀδούς (όδοντ-) = Ε. tooth .] A term descriptive of a form of lophodont dent i- tion in which the crests or folds of the crowns of the molar teeth are alternate: opposed to antiodont. amœboid (a-mē'boid), a. and n. [ amæba + -oid.] I. a. Of, pertaining to, or resembling an ameba: as, amaboid ma es. It is not uncommon for portions of the protoplasmic substance to pa into an amœboid condition. Sir T. Browne , Vulg. Err. I stood IMG:content-0638.png:[blocks in formation] 3. By the joint action or consent of; with the common aid or knowledge of: as, settle it among yourselves; the mischief was done among you. You have, among you, killed a sweet and innocent lady. Shak., Much Ado, v. i. 4. To each of; by or for distribution to: as, he gave five dollars to be divided among them. What are they [five loaves and two fishes] among so many? John vi. 9. 5t. In the circumstances of; during the time or term of; in the course of. Amœboidea (am-e-boi'de-a), n . pl . [NL., Amaba + -oidea.] An order of amœbiform rhizopodous Protozoa , of which the genus Ama- ba , of the family Amabida , is the type. This order is practically distinguished from Monera by the presence of a nucleus, and from the Foraminifera and Radio lari a by the absence of a complete calcareous or si- licious shell. The terms Amœboidea , Amœbin a , Amœbӕа , and Amœbæ (see Amaba ) are more or le nearly synony. mous; but the definition of the groups of amæbiform ani- mals varies with almost every leading writer. See amœba . amœbous (a-mē'bus), a . [ amaba + -ous.] Of or pertaining to the genus Amaba ; resem- bling an amœba in structure. Also amaban. amœbula (a-mē bū-la), n.; pl. amæbulæ (-lē). [NL., dim. of amaba . ] A little ameba. E. R. 2. At intervals; here and there. I never went to any place among all my life.. which I had before Baxter , in Tulloch's Eng. Puritanism, p. 306. ( N. E. D. ) Lankester , Encyc. Brit., XIX. 840. a me no mania (a-me-nō-ma'ni-a), n. [NL., amænus , pleasant (see amene ), + mania , For le ynggis [leasings] wyll lepe out amonge , That oftyn brewis ballys [bales, mischiefs]. The Good Wyfe wold a Pylgremage , 1. 85. (E. E. T. S., [extra ser. VIII., i. 41.) They [the fowles] sate amonge Upon my chambre roofe withoute, Upon the tyles over al aboute. among 3. Between whiles; at intervals; from time to time; now and then.-4. During the time; meanwhile. =Syn. Amid, In the midst of, Among, Be tween, Betwixt. The midst is the middle place; hence amid or in the midst of should be used where a person or thing is in a position which is, or may be imagined to be, central; they are naturally the expre ions between which to choose when the noun is in the singular, or a plural noun stands for that which is virtually one: as, "Lo, I see four men loose, walking in the midst of the fire" (Dan. iii. 25); amid the waves. By derivation among suggests a mingling; it may be properly used with collective nouns: as, he disappeared among the crowd. Between is nearly equiv. among refers to more than two; it is therefore improper alent etymologically to by twain, so applying to two; to say either among them both, or between the three. Be twixt is the same as between. Plac'd far amid the melancholy main. Thomson, Castle of Indolence, i. 30. Where two or three are gathered together in my name, there am I in the midst of them. Mat. xviii. 20. IMG:content-0639.png:[blocks in formation] Shak., 1 Hen. IV., i. 1.