GLOSSARY 419 



En'doskeleton (Gr, p.ndon, within ; skeletos, hard) : a skeleton inside the body 

 as opposed to the outer or exoskeleton. 



En'dosperm (Gr. endon, within) : food stored in the seed outside the embryo. 



En'ergy (Gr. energos, at work) : work power ; abiHty to perform work. It 

 may be latent or kinetic. 



Envi'ronment (Fr. environ, about) : the surroundings of an organism. 



En'zyme (Gr. en, in ; zyme, leaven) : a substance which brings about a chemical 

 action, assisting in digestion. 



Epider'mis (Gr. epi, upon ; derma, skin) : an outer layer of cells ; the outside 

 skin. 



Epiglot'tis (Gr. epi, upon ; glotta, tongue) : a covering over the opening into 

 the trachea. 



Ero'sion (Lat. erodere, to gnaw off) : the wearing away of rocks by water, 

 wind, glaciers, and other agents. 



iSsoph'agus : muscular tube leading from the pharynx to the stomach ; gullet. 



Essen'tial organs : the stamens and pistils, parts of a flower which have to do 

 with the production of seeds. 



Eugenics (Gr. eugenes, well born) : the science which deals with race improve- 

 ment through heredity. 



Eusta'chian tube : the canal connecting the tympanic cavity with the pharynx, 

 named for its discoverer, Eustachio, an Italian physician. 



Euthen'ics (Gr. euthenein, to thrive) : the science which deals with race im- 

 provement through betterment of the environment. 



Excre'tion : elimination of waste products from an organism. 



Exoskereton : an outside skeleton. 



Fatigue' (Lat. fatigare, to weary) : the effect produced by prolonged stimula- 

 tion on the cells of an organism. 

 Fats : a class of nutrients composed of much carbon and hydrogen with a little 



oxygen. 

 Fermenta'tion (Lat. fermentum, ferment) : the chemical transformation of 



organic substances through the agency of enzymes or ferments, or through 



the agency of bacteria. 

 Fertiliza'tion (Lat. fertilis, fruitful) : the union of an egg cell and a sperm cell. 

 Fibrovas'cular bundles : collections of tubular cells, supported by woody 



cells, which conduct fiuids^in plants. 

 Fin : a fold of skin, with skeletal supports, used for swimming. 

 Fis'sion (Lat. fissum, cleft) : division of a cell into two cells of equal size. 

 Flagerium (Lat. flagellum, whip) : a vibratory threadlike projection of certain 



cells. 

 Fo'cal inf ec'tion : a center of bacterial infection, often at the base of a tooth, 



from which toxins reach the blood. 

 Food : a substance that forms the material for the growth or repair of the 



body of a plant or an animal or that furnishes energy for it. 



