624 Our Surroundings 



Endosperm (en'do-spurm) : Reserve food stored in a seed outside the 



embryo. 



Energy: Capacity for doing work. 

 Environment: Surroundings. 

 Enzyme (en'zim) : Any one of the ferments in the body which aid in 



digestion. 

 Epicotyl (ep-i-kot'il) : The part of the seedling that develops into the 



stem and leaves. 

 Epidermis (ep-i-dur'mis) : The outer skin; the outermost layer of cells 



covering the surface of a plant. 

 Epiglottis (ep-i-glot'is) : A small organ which covers the opening of the 



trachea, or windpipe. It opens to allow the entrance of air, and closes 



to keep out food. 

 Equator: An imaginary line around the earth halfway between the poles, 



dividing it into a northern and a southern hemisphere. 

 Equatorial calms: A belt near the equator where there is little wind. 

 Erosion: The act of wearing away, as rock and soil are worn away by 



the action of water. 

 Esophagus (e-sof'd-gits) : The tube through which food and drink pass 



from the mouth to the stomach ; sometimes called the gullet. 

 Ether: A medium which is said to fill all space. 

 Ethyl alcohol: Alcohol made from grains. 

 Eustachian tube (u-sta'ki-an) : The passage connecting the middle ear 



with the mouth. 

 Evaporate: To change from a liquid or solid state into vapor by means 



of heat. 

 Excretion (Plural Excreta) : Waste thrown off by any organism ; the 



process of throwing off waste. 



Excretory organs (eks'kre-to-ri) : Organs that give off bodily wastes. 

 Exhale: To breathe out, or emit. 



Experiment: An attempt to discover, test, or prove some truth or prin- 

 ciple. 



Expiration (ek-spi-ra'shwn) : Breathing out. 

 Extensor muscle (eks-ten'sor) : Any muscle which extends or straightens 



a limb. 

 Eye: The organ of sight. 



Fahrenheit (fa'ren-hit) : A thermometer scale on which the freezing 



point of water is 32 and the boiling point 212. 

 Fainting: Loss of consciousness caused by insufficient supply of blood 



to the brain. 

 Farsightedness: Inability to see near-by objects as clearly as distant 



objects. 

 Fatigue (fd-teg') : Weariness resulting from over-working of the cells 



of an organism. 

 Fats: Energy-producing nutrients composed of carbon, hydrogen and a 



little oxygen. 



Fauna (fo'nd) : The native animals living within a certain region. 

 Fehling's solution (fa'lmgz) : A liquid used to test for the presence of 



grape sugar. If grape sugar is present, Fehling's solution produces a 



color from deep yellow to brick-red, according to the amount of grape 



sugar present. 

 Femur (fe'mwr) : The long bone of the thigh. 



