Part 77

Act"ing (&?;), a. 1. Operating in any way.

2. Doing duty for another; officiating; as, an acting superintendent.

||Ac*tin"i*a (&?;), n.; pl. L. Actiniæ (&?;), E. Actinias (&?;). [Latinized fr. Gr. &?;, &?;, ray.] (Zoöl.) (a) An animal of the class Anthozoa, and family Actinidæ. From a resemblance to flowers in form and color, they are often called animal flowers and sea anemones. [See Polyp.]. (b) A genus in the family Actinidæ.

Ac*tin"ic (&?;), a. Of or pertaining to actinism; as, actinic rays.

Ac*tin"i*form (&?;), a. [Gr. &?;, &?;, ray + -form.] Having a radiated form, like a sea anemone.

Ac"tin*ism (&?;), n. [Gr. &?;, &?; ray.] The property of radiant energy (found chiefly in solar or electric light) by which chemical changes are produced, as in photography.

Ac*tin"i*um (&?;), n. [Gr. &?;, &?;, ray.] (Chem.) A supposed metal, said by Phipson to be contained in commercial zinc; -- so called because certain of its compounds are darkened by exposure to light.

Ac`ti*no-chem"is*try (&?;), n. Chemistry in its relations to actinism. Draper.

Ac*tin"o*graph (&?;), n. [Gr. &?;, &?;, ray + -graph.] An instrument for measuring and recording the variations in the actinic or chemical force of rays of light. Nichol.

Ac"tin*oid (&?;), a. [Gr. &?;, &?;, ray + -oid.] Having the form of rays; radiated, as an actinia.

Ac*tin"o*lite (&?;), n. [Gr. &?;, &?;, ray + -lite.] (Min.) A bright green variety of amphibole occurring usually in fibrous or columnar masses.

Ac`tin*o*lit"ic (&?;), a. (Min.) Of the nature of, or containing, actinolite.

Ac`ti*nol"o*gy (&?;), n. [Gr. &?;, &?;, ray + -logy.] The science which treats of rays of light, especially of the actinic or chemical rays.

Ac*tin"o*mere (&?;), n. [Gr. &?;, &?;, ray + &?; part.] (Zoöl.) One of the radial segments composing the body of one of the Cœlenterata.

Ac`ti*nom"e*ter (&?;), n. [Gr. &?;, &?;, ray + -meter] (a) An instrument for measuring the direct heating power of the sun's rays. (b) An instrument for measuring the actinic effect of rays of light.

Ac`ti*no*met"ric (&?;), a. Pertaining to the measurement of the intensity of the solar rays, either (a) heating, or (b) actinic.

Ac`ti*nom"e*try (&?;), n. 1. The measurement of the force of solar radiation. Maury.

2. The measurement of the chemical or actinic energy of light. Abney.

Ac`ti*noph"o*rous (&?;), a. [Gr. &?;, &?;, ray + &?; to bear.] Having straight projecting spines.

Ac*tin"o*some (&?;), n. [Gr. &?; ray + &?; body.] (Zoöl.) The entire body of a cœlenterate.

Ac"tin*ost (&?;), n. [Gr. &?;, &?;, ray + &?; bone.] (Anat.) One of the bones at the base of a paired fin of a fish.

Ac*tin"o*stome (&?;), n. [Gr. &?;, &?;, a ray + &?; mouth.] (Zoöl.) The mouth or anterior opening of a cœlenterate animal.

||Ac`ti*not"ro*cha (&?;), n. pl. [NL.; Gr. &?;, &?;, a ray + &?; a ring.] (Zoöl.) A peculiar larval form of Phoronis, a genus of marine worms, having a circle of ciliated tentacles.

||Ac"ti*no*zo"a (&?;), n. pl. [Gr. &?;, &?;, ray + zw^on animal.] (Zoöl.) A group of Cœlenterata, comprising the Anthozoa and Ctenophora. The sea anemone, or actinia, is a familiar example.

Ac`ti*no*zo"al (&?;), a. (Zoöl.) Of or pertaining to the Actinozoa.

||Ac"ti*no*zo"ön (&?;), n. (Zoöl.) One of the Actinozoa.

||Ac*tin"u*la (&?;), n. pl. [NL., fr. Gr. &?;, &?;, a ray.] (Zoöl.) A kind of embryo of certain hydroids (Tubularia), having a stellate form.

Ac"tion (&?;), n. [OF. action, L. actio, fr. agere to do. See Act.] 1. A process or condition of acting or moving, as opposed to rest; the doing of something; exertion of power or force, as when one body acts on another; the effect of power exerted on one body by another; agency; activity; operation; as, the action of heat; a man of action.