E P I 



E Q U 



extremely delicate and diaphanous on 

 some parts of a flower, and very thick, 

 hard, and coarse, on the trunks of many 

 trees. 



EPIDI'DYMIS. (etrididvplG, from STTI, and 

 SiSv/jiog, Gr.) A body principally com- 

 posed of minute, tender, elastic tubes, 

 intricately convoluted, termed tubuli 

 seminiferi, and placed at the outer and 

 back part of the testis. 



E'PIDOTE. The Prismatoidischer Augit- 

 spath of Mohs, and Pistazit or Pistacite 

 of Werner. A mineral of a green or grey 

 colour ; a subspecies of prismatoidal au- 

 gite. It occurs regularly crystallized, in 

 granular, prismatic, and fibrous concre- 

 tions, and is said to derive its name from 

 the Greek word 7rt'<5(.$ai/ii, from an en- 

 largement of the base of the prism in one 

 direction. It is brittle and easily broken. 

 It is found, principally, in primary 

 rocks, and in many parts of Scotland, as 

 well as in England, Norway, France, 

 &c. It consists of silica 37'0, alumina 

 27*0, lime 14-0, oxide of iron 17'0, oxide 

 of manganese 1'5. There are many va- 

 rieties. 



EPIGA'STRIC. (from i-rri, above, and 

 yaffTrjp, the belly, Gr. epigastrique, Fr.) 

 Belonging to the upper part of the abdo- 

 men, or epigastric region. 



EPIGA'STRIUM. (tTrtyairrpiov, Gr. epigas- 

 trium, Lat. epigastre, Fr.) The upper 

 part of the abdomen or belly. 



EPIGLO'TTIS. (epiglottis, Lat. cpiglotte, 

 Fr. STriyXwffo-tc, vel iTrtyXwrric, Gr. 

 membrana cartilaginosa rotunditatis ob- 

 longse gutturi claudendo et reserando.) 

 One of the five cartilages of the larynx, 

 situated above the glottis, whose use is to 

 close the glottis during the act of swal- 

 lowing and thereby to prevent the pas- 

 sage of food into the trachea, or windpipe. 



EPIPHYLLOSPE'RMOUS. (from STTI, QvXXov, 

 and <77Tp/*a, Gr.) A term in botany, 

 applied to plants bearing their seed on 

 the back part of their leaves. 



EPI'PHYSIS. (7ri0w<7ic, from 7ri0i5o>, 

 Gr.) A process of bone attached to a 

 bone, but not being a part of the same 

 bone, as is the case of apophysis. 



EPI'PLOON. (fc7rt7rXoor,from tTrtTrXew, Gr. 

 epiploon, Fr.) The omentum, or caul; 

 that membranous expansion which hangs 

 from the bottom of the stomach and co- 

 vers the intestines. 



EPIZOO'TIC. (from STU and %u>ov, Gr.) 

 Containing animal remains, as epizootic 

 hills, or epizootic strata. 



E'POCH. (ITTOX?/, Gr. epocha, Lat. epoque, 

 Fr. epoco, It.) A term literally signify- 

 ing a stop, a fixed point of time, from 

 which succeeding years are numbered ; 

 the period at which a new computation, 

 or reckoning, is begun. 



EPO'CHA. (Lat.) The same as epoch. 



ECIUA'NGULAR. (from cequus and angulus, 

 Lat.) The harshness of this word has 

 caused it to be supplanted by equiangu- 

 lar, one far more euphonic. Consisting 

 of equal angles ; having equal angles. 



EQUA'TOR. (equateur, Fr. (equator, Lat. 

 equatore, It.) A great circle of the 

 sphere, equally distant from the two 

 poles of the world, or having the same 

 poles with those of the world. It is 

 called the equator, because when the sun 

 is in it, the days and nights are equal ; 

 whence also it is called the equinoctial. 

 Every point of the equator is a quad- 

 rant's distance from the poles of the 

 world ; whence it follows, that the equa- 

 tor divides the sphere into two hemi- 

 spheres, in one of which is the northern, 

 and in the other the southern pole. 



EftUAxo'RiAL. Pertaining to the equa- 

 tor : the equatorial diameter of our 

 planet exceeds its polar diameter by 

 about 27 miles ; the length of the equa- 

 torial diameter being 7927 miles, that of 

 the polar 7900. 



EauiA^NGULAR. (from cequus and angu- 

 lus, Lat. tquiangule, Fr. equiangolo, It.) 

 A figure whose angles are all equal ; con- 

 sisting of equal angles ; having equal 

 angles. 



EQUICRU'RAL. (from cequus and crus, 

 Lat.) Having all its legs of equal 

 length. 



EQUIDI'FFERENT. Arithmetically propor- 

 tional ; having equal differences. 



EQUIDI'STANT. (Equidistant, Fr. equidis- 

 tante, It.) Being at equal distance 

 from some one point. 



E'CIUIFORM. (cequiformis, Lat.) Having 

 the same shape, form, or make. 



EQUIFO'RMITY. Likeness, or resemblance, 

 in form ; uniform equality. 



EQUILA'TERAL. (cequilatus and cequila- 

 terus, Lat. equilateral^ Fr. equilatero, 

 It.) Having all the sides equal. In 

 conchology, shells whose sides are alike,, 

 as in those of ostrsea ; or when a line 

 drawn perpendicularly from the apex of 

 a bivalve would cut it into equal parts. 



EQ,UI'NAL. > (equinus, Lat.) Pertaining 



E'QUINE. 5 to a horse ; relating to a 

 horse. 



EQUISETA'CE^E. (from equisetum, horse- 

 tail.) The plants are known in this 

 country as the horse-tail of our ditches. 

 Equisetacese are found both fossil and 

 recent. M. Ad. Brongniart has, in 

 his "Histoiredes Vegetaux Fossiles,' r 

 divided fossil equisetacese into two ge- 

 nera ; the one exhibits the characters of 

 living equiseta, and as a fossil is rare ; 

 the other differs greatly in its form, fre- 

 quently attaining an immense magnitude ; 

 these last have been arranged under the 



