EPICOTYLEDONES 



11* 



EQUATOR 



Epicotyledones, (ep-i-kot-i-le'donz). [Epi and 

 Cotyledon, q.v.] Van Beneden's term for In- 

 sects, Myriapoda, Arachnida, and Crustacese. 



Epicrium. A snake-like reptile, belonging to 

 Ophiomorpha, found only in Asia. 



Epicycle, (ep-i-si'kl). [Gk. epi, upon ; kyklos, 

 circle.] A small circle revolving upon the 

 circumference of a larger circle. 



Epicycloid, (ep-i-si'kloid). [Epi and Cycloid, 

 q.v.] A curve traced by a point in the cir- 

 cumference of one circle which is rolling 

 upon the convex arc of another circle. 



Epicyclic trains, (ep-i-si'klik). [Epicycle, q.v.} 

 A number of wheels attached to a rotating 

 bar, from the revolutions of which they 

 derive their motion. 



Epidemic,(ep-i-dem'ik). [Gk. epi, upon ; demos, 

 people.] Diseases prevailing amongst numbers 

 of persons at the same time. cf. Endemic. 



Epidermal, (ep-i-der'mal). [Epidermis, q.v.} 

 =Epidermic: connected with, or related to, 

 the epidermis. 



Epidermis, (ep-i-der'mis). [Epi and Dennis, 

 q.v.} The outer tough layer of skin, composed 

 of horny matter, which contains no blood- 

 vessels, and is continually being worn away 

 and replaced. 



Epidermose, (ep-i-der'mos). [Epidermis, q.v.} 

 := Epidermal, q.v. 



Epidote. (ep'i-dot). [Gk. cpididomi, I add to.] 

 A mineral of the garnet group, a silicate of 

 alumina and liuie. 



Epigee, (ep'i-ge). [Gk. epi, upon; ge, earth.] 

 v. Perigee. 



Epigenesis, (ep-i-jen'e-sis). [Epi and Genesis, 

 q.v.] A method of reproduction, in which 

 the individual is supposed to grow rather 

 than to develop; opposed to Evolution, q.v. 



Epigenite, (ep'i-jen-It). A mineral, chiefly 

 sulphide of iron and copper. 



Epiglottis, (ep-i-glot'tis). [Epi and Glottis, 

 q.v.] The gristly covering of the glottis, q.v. 



Epigynous, (e-pij'i-nus). [Gk. epi, upon; 

 gyne, woman.] Having calyx, corolla, and 

 stamens all adhering to ovary, and the ovary 

 consequently inferior. 



Epihyal, (ep-i-hfal). [Epi and Hyoid, q.v.] 

 A bone of the hyoid arch in fishes. 



Epilobium, (ep-i-16'bi-um). [Gk. epi, upon; 

 lobos, lobe.]=Willow-herb : an herb belong- 

 ing to Onagracese. 



Epimachus, (e-pim'a-kus). [Gk. epimachus, 

 defenceless. ]=Plume birds. 



Epiornis=.^Epiornis, q.v. 



Epiotic, (ep-i-ot'ik). [Gk. epi, upon; ous, ear.] 

 The upper bone of the auditory capsule in 

 the ear. 



Epipactis, (ep-i-pak'tis)=Helleborine, an herb 

 belonging to Orchidaceae. 



Epipastics, (ep-i-pas'tiks). [Gk. epipasso, I 

 moisten.] = Vesicatory: raising blisters. 



Epiphlc3um, ( ep-i-fle'um ). [Gk. epi, upon; 

 phloios, bark.]=Corky-bark: the outermost 

 of the three layers, of which bark is usually 

 composed. 



Epiphragm, ( ep'i-fragm ). [Gk. epi, upon ; 

 phragmo,, fence.] The barrier of hardened 

 mucus with which snails, &c., close the orifice 

 of their shells. 



Epiphysis, (e-pif'i-sis). [Gk. epi, upon; pliyo, 



I grow.] Any process or projecting portion, 



especially of a bone. 

 Epiphyte, (ep'i-fit). [Gk. epi, upon; phytos, 



planted.] A plant attached to another plant, 



but not growing at its expense, v. Orchi- 



dacese. cf. Parasitic plants. 

 Epiphytic, (ep-i-fit'ik). [Epiphyte, q.v.] Hav- 



ing the qualities of, or being related to, 



epiphytes. 

 Epipodia, (ep-i-po'di-a). [Gk. epi, upon; pous, 



foot.] Lobes upon the feet of some Gas- 



teropoda. 

 Epipodite, ( ep'i-pod-it ). [Gk. epi, upon; 



pous, foot.] The external distal segment of 



the limb of a crustacean animal. 

 Epistome, (ep'is-tom). [Gk. epi, upon ; stoma, 



mouth.] A valve-like organ, arching over 



the mouth in some Polyzoa. 

 Epistylion, (ep-is-ti'li-oii). [The Greek word.] 



= Architrave, q.v. 

 Epithelium, (ep-i-theli-um). [Gk. epi, upon ; 



thelys, soft flesh.] The modified epidermis 



which forms the outer layer of the mucous 



membrane. 

 Epitricha. A ' sub-division of Infusoria, v. 



Hoeven. 



Epizoa, (ep-i-zo'a). [Gk. epi, upon; zoon, 

 ; animal.] = Haustellata : parasitic Crustacea, 



with suctorial mouths; free when young, 



parasitic when adult. 

 Epizoon, (ep-i-zo'on). [Gk. epi, tipon ; zoon, 



animal.] Singular of Epizoa, q.v. 

 Epizootic diseases, ( ep-i-zo-ot'ik ). [Epizoa, 



q.v.} Sheep- pox, glanders, &c.: diseases to 



which cattle are subject, cf. Epidemic. 

 Epoch, (e'pok). [Epochc, the Greek word.] 



1. Any time from which dates are counted: 



any remarkable event which is taken as a 



standard in chronology. 2. In astronomy, 



the position of a star at a given date. 

 Epsom salts, [First found in springs at 



Epsom.]=MgSO4=Magnesic sulphate. 

 Epsomite, (ep'som-it). A mineral, chiefly sul- 



phate of magnesium. 

 Equation, (e-kwa'shun). [L. aiquatio, a making 



equal.] The expression of equality : Ex. 



1+5 = 4+2. Binomial E. = x - A = 0. v. 



Binomial. Biquadratic E. = x t +2'>^+ < l^+ 



rx + s = 0. Cubic JE. = y?+ax 2 +bx+c = 0. 



Quadratic E. = x z + px+q = r. If the un- 



known quantity occur in only the first power, 

 X, the equation is simple; if in the second 

 power, x-, it is quadratic ; if in the third 

 power, x , it is cubic; in the fourth power, 

 x*, it is biquadratic. E. of a circle : (x-h)-+ 

 (y k'p=a'' i , in which a=radius; M-=centre; 

 xy=any given point. E. of a line : Ax+ 

 B?/=C, x and y being the co-ordinates, q.v. 

 E. of time : the time to be added to, or sub- 

 tracted from, the time shown by a sun-dial, to 

 find the correct time. 



Equator, (o-kwa'tor). [L. cequatio, a making 

 equal.] An imaginary line drawn on the 

 surface of the earth, midway between tho 

 poles, so as to divide its surface equally- 

 Magnetic E., a line approximating to a 

 great circle of the earth; also called Aclinic 

 line, q.v. 



