EPIDENDRUM 



EPIGRAM 



for influenza. Search must be 

 made for any causative factor, 

 particular attention being paid to 

 the purity of food and drinking 

 water. Accumulations of filth or 

 rubbish should be removed. In 

 fact, cleanliness both of habita- 

 tion and person is an important 

 feature in the prevention of epi- 

 demics. See Plague ; Public Health. 

 Epidendruzn (Gr. epi, on ; 

 dendron, tree). Large genus, main- 

 ly of epiphytes, of the natural order 

 Orchidaceae. They are natives 

 chiefly of S. and Central America 



Epidendrum. Flower bud and leaves 



and the W. Indies. They have 

 leathery, strap-shaped leaves, and 

 flowers solitary or disposed in 

 spikes and sprays. The character- 

 istic features of the genus are the 

 union (more or less complete in 

 different species) of the fleshy base 

 of the Kp to the column, a passage 

 at the base of the lip, and the four 

 compressed pollen-masses. Some 

 of them have handsome flowers, 

 but in many species these are of a 

 dingy green hue. 



Epidermis (Gr. epi, on ; derma, 

 skin). Name for the superficial 

 layer of the skin, lying above the 

 cut is vera or true skin. It is formed 

 by a number of layers of cells, the 

 most superficial of which consist 

 of stratified epithelium, and are 

 horny in character. These form the 

 thickest part of the epidermis. 

 Beneath the horny layers are 

 several layers of clear rounded 

 cells forming the stratum lucidum; 

 next is a layer of granular cells, 

 the stratum granulosum. In these 

 strata the change from protoplasm 

 to horny material takes place. The 

 deepest layers constitute the rete 

 mucosum or Malpighian layer, and 

 consist of soft protoplasmic cells. 

 The epidermis grows from the 

 deeper layers, the superficial horny 

 cells being continually shed. It has 

 no blood vessels, but fine nerves 

 ramify in the deeper layers. See 

 Anatomy; Skin. 



Epidiascope (Gr. epi, on ; dia t 

 through ; skopein, to look). Ap- 

 paratus of the optical lantern type. 



Originally intended for projecting 

 on to a screen images of opaque 

 bodies such as insects, coins, dia- 

 grams, etc., in their natural colours, 

 it may also be used for projecting 

 transparent objects, e.g. lantern 

 slides and microscopic preparations 

 may be shown with considerable 

 magnification. The illumination is 

 obtained from an arc lamp located 

 at the focus of a parabolic mirror ; 

 the light is thrown upon, or trans- 

 mitted through, the object by a 

 system of condensers and mirrors. 

 Means are provided to effect the 

 change over from transmitted to 

 reflected light, or vice versa. 



Epididymis (Gr. epi, on ; didy- 

 mos, testicle). In anatomy, a con- 

 voluted tube which receives the 

 ducts from the testicle, and is pro- 

 longed into a tube, the vas deferens, 

 through which semen passes to the 

 urethra. 



Epidiorite (Gr. epi, on ; dior- 

 ite). Crystalline rock much altered 

 by metamorphism. It is composed 

 of the minerals hornblende and 

 felspar, and sometimes a little 

 quartz. Hornblende is the result of 

 alteration of augite in the original 

 rock, the felspar is granular, and all 

 constituents rearranged. It occurs 

 as large intrusive sheets with 

 schists in the Scottish highlands 

 and N. Ireland. See Diorite. 



Epidote (Gr. epi, on, besides ; 

 dotos, given). Hydrous silicate of 

 calcium and aluminium. It is 

 found abundantly, but outside 

 Austria and America is rarely of 

 sufficient transparency and fine 

 colour to be cut as a precious stone. 

 The colour ranges from green to 

 brown. Its specific gravity is from 

 3'25 to 3'5 ; it stands low in the 

 scale of hardness. Piedmondite is a 

 manganese epidote found in Pied- 

 mont, some valued specimens 

 being characterised by a magni- 

 ficent cherry-red colour. Epidote 

 is so called because the base of the 

 primary crystals is enlarged in 

 some of the secondary forms. 



Epigastrium (Gr. epi, on ; 

 gaster, belly). Upper central por- 

 tion of the abdomen, or pit of the 

 stomach. 



Epigenesis (Gr. epi, on ; gene- 

 sis, generation). Term used in bio- 

 logy to express the development of 

 an organism as the result of the 

 growth and subsequent differen- 

 tiation of a single germ -cell into the 

 complicated tissues of an indivi- 

 dual. This takes place by the seg- 

 mentation or division of the fer- 

 tilised cell. See Biology ; Cell ; Re- 

 production. 



Epiglottis (Gr. epi, on ; glossa, 

 glotta, tongue). Thin leaf -shaped 

 structure, consisting of fibro-carti- 

 lage, placed behind the root of the 

 tongue and in front of the superior 



opening of the larynx. It was 

 formerly supposed that it was bent 

 back during the act of swallowing 

 and served as a lid to close the 

 larynx ; but it is now recognized 

 that the closing of the glottis is 

 effected by the arytenoid and thyro- 

 arytenoid muscles. 



Epigoni (Gr. descendants). In 

 Greek legend, the_sons of the seven 

 heroes who fell in the war against 

 Thebes. See Adrastus. 



Epigram (Gr. epi, upon ; gram- 

 ma, a writing). Originally a simple 

 inscription attached to religious 

 offerings. It was afterwards writ- 

 ten on the temple gate, and by 

 easy transition passed to other 

 public edifices and to statues of 

 gods, heroes, and all who had dis- 

 tinguished themselves by patriot- 

 ism, courage, and virtue. The 

 term at first included inscriptions 

 in verse or prose, and the form was 

 employed by legislators and phil- 

 osophers to convey any political or 

 moral precept, its brevity impress- 

 ing it readily upon the memory. 

 Finally, among the Greeks, the 

 epigram came to signify any short 

 piece of poetry which conveyed a 

 single idea with neatness and grace. 

 The Greek Anthology contains 

 epigrams characterised by delicacy 

 and truth of sentiment, and by 

 elegance of expression, and entirely 

 devoid of satire, play upon words, 

 and even of conceit. Even in the 

 lighter convivial epigrams the 

 thought is generally of a melan- 

 choly cast, and the sepulchral in- 

 scriptions are remarkable for their 

 simple delicacy and their perfect 

 appropriateness. 



In the hands of the Latin epi- 

 grammatists the epigram acquired 

 a new character. The term was 

 now applied to 

 any brief and 

 concise composi- 

 tion in prose or 

 verse, in which 

 a single idea was 

 expressed and 



the point made 

 b y antithesis, 

 surprise, or play 

 upon words. 

 Catullus and 

 Martial are the 

 acknowledged 

 masters of the 

 Latin verse epi- 

 gram, Tacitus of 

 its prose equiva- 

 lent. Despite 

 much concert 

 and some ob- 

 scenity Catul- 

 lus excelled all 

 other Roman 



Epiglottis seen from 

 the front. Above, 

 sectional diagram 

 showing position of 

 this structure in the 

 throat 



