E X O 



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F A L 



outside of their wood, as the name 

 implies. See the etymology of Exo- 

 genous. 



EXO'GENOUS. (from t'w and yevvaw, Gr.) 

 Plants in which the growth takes place by 

 additions from without, or by external 

 increase. 



E'XOLETE. (exoletus, Lat.) Worn ; faded. 



EXO'SSATED. (exossatus, Lat.) Deprived 

 of bones. 



EXO'SSEOUS. (from ex and ossa, Lat.) 

 Destitute of bones ; animals not possess- 

 ing bones. 



EXOSTO'SIS. (from t% and 6oreov, Gr.) A 

 diseased growth of bone. 



EXO'TIC. (exoticus, Lat. gartKO, Gr. 

 exotique, Fr. esotico, It.) In botany, 



plants not natives of the countries in 

 which they are cultivated. 



EXSANGUINE'OUS. ) (fromexet sanguineus, 



EXSA'NGUINOUS. $ Lat.) Bloodless ; 

 without red blood. 



EXTE'NSOR. (from extendo, Lat. extenseur, 

 Fr.) The name of such muscles as ex- 

 tend or straighten the parts, and serve as 

 antagonist muscles to the flexors. 



E'XTIRPATE. (extirpo, Lat. extirper, Fr. 

 esterpare, It.) To entirely destroy ; to 

 root up ; to eradicate. 



EXU'VI^E. (Lat.) Cast shells ; cast skins ; 

 organic remains. 



Exu' VIABLE, That may be cast or thrown 

 off, as the skeletons of articulated ani- 

 mals. 



FABA'CEOUS. (fabaceus, Lat.) Of the 

 nature of a bean ; resembling a bean. 



FACE, (face, Fr. facda, It. fades, Lat.) 

 One of the figures which compose the su- 

 perficies of a body ; the surface which 

 presents itself to the sight. Polyhedrons 

 have several faces ; a cube has six faces. 



FA'CET. (facetta, It.facette, Fr. run des 

 c6ts d'un corps qui a pltisieurs petits 

 cot6s.) A superficies cut into several 

 angles. 



FA'CIAL. (from fades, Lat. facial, Fr.) 

 Belonging to the face, as the facial nerves, 

 &c. 



F'ACIAL ANGLE. An angle composed of 

 two lines, one drawn in the direction of 

 the base of the skull, from the ear to the 

 roots of the superior incisores, the other 

 from that point to the superciliary ridge 

 of the frontal bone. 



FACTITIOUS, (factitius, Lat.) Made by 

 art as contrary to that formed by nature : 

 thus we have factitious waters and facti- 

 tious stones. 



F^E'CAL. (from faces, Lat.) Containing 



F^E'CES. (f<RX t Lat. used plurally only.) 

 Excrement ; sediment. The fossil faeces 

 of certain fishes are called coprolites ; the 

 excrement of dogs and wolves, album grse- 

 cum ; of mice, album nigrum. 



FA'HLUNITE. (from Fahlun, in Sweden, 

 where it is found.) Automolite, or oc- 

 tahedral corundum. See Automolite. 



FAIRY-RING. In meadows and grass-lands, 

 circles of a different hue from the sur- 

 rounding grass are often seen ; these are 

 commonly called fairy-rings, from a vul- 

 gar saying that at night fairies dance there- 

 on. The true cause of these appearances, 

 which have excited the astonishment of 

 many, is as follows; they are external 



indications of the centrifugal growth of 

 the subterranean stems of certain agarics, 

 which, originally springing from a com- 

 mon point, continually spread out- 

 wards upon the same plane, the centres, or 

 first formed parts, perishing as the cir- 

 cumference, or last formed parts, develope 

 themselves. 



FAIRY-STONE. A. name sometimes given 

 to the echinite. 



FA'LCATE. A figure formed by two curves 

 bending the same way, and meeting in a 

 point at the apex, the base terminating 

 in a straight margin, resembling a sickle. 



FA'LCATED. (falcatus, Lat.) Hooked; 

 crooked like a reaping-hook. 



FALCA'TION. Crookedness. 



FA'LCIFORM. (fromfalx and forma, Lat.) 

 Shaped like a scythe or reaping-hook. 



FALLING-STONE. A meteoric body, com- 

 monly called an aerolite. 



FA'LUN. (Fr. assemblage de coquilles 

 brisdes, qu'on trouve en mass a une cer- 

 taine profondeur de terre.) A provin- 

 cial name given to some shelly strata in 

 the neighbourhood of the Loire, and 

 which resemble, in their lithological cha- 

 racters, what is denominated the crag. 

 The faluns, or marls of Tourraine and the 

 Loire, constitute an extensive formation 

 of marl beds, which are now admitted to 

 be of later date than the most recent of 

 the fresh-water beds in the Paris basin. 

 They are regular depositions, formed du- 

 ring an epoch of tranquillity, and sub- 

 jected to laws of which the action is con- 

 tinued on the present shores. The great 

 mass of fossil shells which these beds con- 

 tain, differ from those of the Paris basin : 

 in nearly 400 species, there are only 

 about 20 identical with the Paris fossils. 

 The terrestrial and river shells are in the 



