dichet

and v. A Middle English form of ditch. Dichelesthiidæ (dikē-les-thi'i-dē), n. pl. [NL., =10 Dichelesthium sturionis, magnified. The typical genus of fish-lice of the family Dichelesthiida. Also written Dichelestium. Hermann, 1804. Dich i to nid a (dī-ki-ton'i-da), n. pl. [NL., cisors. The dichobunes are supposed to have had a diffuse placenta and a tripartite stomach with no developed psalterium, and hence to have been non-ruminant. The dentition is of the pattern called bunodont. The leading genera are Dichobune and Dichodon , from the Eocene. dichogamic (dī-kō-gam'ik), a . [ dichogamy + -ic.] Relating to dichogamy. dichogamous (di-kog'a-mus), a . [ δίχα , in two, + γάμος , marriage.] In bot . , exhibiting or characterized by dichogamy. IMG:content-2584.png:[blocks in formation] dichotomous (dī-kot'ō-mus), a. [ tomos , Gr. διχοτόμος, cutting in two, propar- oxytone διχότομος , cut in two, divided equally, Take the cla ification of the sciences, and it is seen that the proce begins at its widest sweep with a pure dichot- omous division: it is the contrast of the Abstract and the Concrete. Specifically-(a) In bot . , regularly dividing by pairs from below upward; two-forked: as, a dichotomous stem. A good example of a dichotomous stem is furnished by the given to the entire stipes. W. B. Carpenter , Micros., § 294. (b) In zool .: (1) Branching by pairs; biramous; bifur- cate; forked: as, the dichotomous division of a deer's ant- lers; the dichotomous foot of a crustacean. (2) Disti- cho us; bifarious; two-rowed or two-ranked; parted in the middle as, the dichotomous hairs of a squirrel's tail. (c) In cla ification , binary; dual; arranged in two ranks or series; opposed by pairs, as a set of characters, or a number of objects characterized by dichotomization. Also dichotomic. - Dichotomous key or table, in nat . hist ., a tabular guide to the orders, genera, etc., as of a flora, ar- ranged artificially, so that by a series of contrasts and ex- clusions the desired order is finally reached. dichotomously (di-kot'ō-mus-li), adv . In a dichotomous manner; by subdivision into two parts or into pairs. Also dichotomic ally . Nor contented with a general breach or dichotomy with their church, [they] do subdivide and mince themselves almost into atoms. Sir T. Browne , Religio Medici, i. 8. Specifically-( a ) In logic , the division of a whole into two parts; binary cla ification. Ramus revived, against the Aristo tel i ans, the Platonic doctrine, which has had many adherents, that all cla ification should be by dichotomy. But the opinion has found little favor since Kant. We cannot by any logical dichotomies accurately expre relations which, in Nature, graduate into each other in sensibly. pears bisected or shows only half its disk, as at the quad- ratures. (c) In bot ., a mode of branching by constant forking, as is shown in some stems, the vena- tion of some leaves, etc. This mode of branching in plants is variously modified, as when only one of the branches at each fork becomes further developed, in which case the dichotomy is said to be sympodial . If these unde- veloped branches lie always upon the same side of the axis, the sym- Inflorescence of Valeria- nella dentata. podial dichotomy is helicoid ; if alternately upon opposite sides, it is scorpioid . Argument from dichotomy, one of the arguments of Zeno the Eleatic against plural- ity and magnitude. Anything hav- ing magnitude must consist of two parts, and those again of two, ad infinitum . Thus, the ultimate parts have no magnitude, and hence not the whole. dichotriæne (dī-kō-tri'ēn), n. [ δίχα , in two, + τρίαινα , a trident: see triæne.] In the nomenclature of sponge-spicules, a dichoto- mous triæne; a cladose rhabdus whose three clad i or arms divide into two. See triæne. The arms of a triæne may bifurcate ( dichotriane ) once, twice, or oftener, or they may trifurcate. IMG:content-2585.png:[blocks in formation] mate.] Same as bichromate . dichromatic (dī-krō-mat'ik), a . [ δι- , two-, + χρώμα(τ-), color: see chromatic. Cf. dichro- mic .] Having or producing two colors; exhib- iting or characterized ized by dichromatism. Also dichroic and bichromatic . dichromatism (dī-kro'ma-tizm), n. [ dichro- mat - ic + -ism .] The quality of being dichromat- ic; the state or condition of normally present- ing two different colors or systems of coloration: in zoöl ., said of animals which, being ordinar i- ly of a given color, regularly or frequently ex- hibit a different coloration, due to melanism, erythrism, etc. The red and gray plumages of many dichroscope (dī'krō-skōp), n. [Irreg. dichroic (di-krō'ik), a . [ δίχροος , two- colored (see dichroous ), + -ic.] 1. Character- ized by dichroism: as, a dichroic crystal. 2. chroscopic observations. Same as dichromatic. dichroscopic (dī-kro-skop'ik), a . [ dichroscope + -ic.] Pertaining to the dichroscope: as, di- dichtings, n. pl. See dightings . dichotomization (dī-kot"ō-mi-zā'shon), n. [ dichotomize + -ation .] Division into two parts; separation or cla ification by dual or binary subdivision. color along the axis, and of a vivid green when viewed 2. A method of decorating leather in squares in a transverse direction. Mica affords another example, being nearly opaque when viewed in one direction, but transparent erty is due to and the of difference a different in color the absorption in another. of This the light prop vibrations in the different directions. See pleochroism. ( b ) The exhibition of e entially different col- ors by certain solutions in different degrees of dilution or concentration. dichroistic (dī-krō-is'tik), a . [ dichro - ism + -istic.] Having the property of dichroism. Also dichroous. dick dick2 (dik), п. [Perhaps