EXI 



156 



EXO 



the separation of a scale or dead 

 portion of bone from the living. 



exindusiate, a., Vks'-m-duz'-i-at (L. 

 ex, out of; indusium, a shirt), in 

 bot., not having an indusium. 



exintine, n., Vks-ln'-tin (L. ex, 

 from ; intus, within), in bot. , one 

 of the inner coverings of the 

 pollen grain. 



exogens, n., %ks'6>jenz (Gr. exo, 

 without ; gennao, I produce), 

 that division of the vegetable 

 kingdom in which the plants 

 grow by additions to the outside 

 of the wood in the form of 

 annual concentric layers, as in 

 the oak, ash, elm, etc. the 'en- 

 dogens ' being those whose growth 

 is from within outwards : exog- 

 enous, a., eJcs-ddf-Zn-tis, growing 

 or increasing in size by annual 

 additions to the outside : exog- 

 enae, n. plu., ^ks-ddf-en-e, an- 

 other name for exogens. 



Exogonium, n., eks'-d-gdn't-um 

 (Gr. exo, without ; gonu, the 

 knee), a genus of plants, Ord. 

 Convolvulaceae : Exogonium 

 purga, perg'-a (L. pur go, I clear 

 or clean out), the jalap plant, a 

 native of the Mexican Andes, 

 whose roots, in size and shape 

 from a walnut to a moderately- 

 sized turnip, form the officinal 

 part ; used in the form of powder 

 and tincture as an active irritant 

 cathartic. 



exomphalos, n., eks-timf-al-fts (Gr. 

 exo, without ; omphalos, a navel), 

 umbilical hernia ; the protrusion 

 of the intestine through the um- 

 bilicus. 



exophthalmos, n., Vks'tif-thal'-rnds, 

 also exophthalmia, n., -thal'-mi-a 

 (Gr. exo, without, outside; oph- 

 thalmos, the eye), great promin- 

 ence of the eyes, in which the 

 individual has a marked and 

 peculiar stare : exophthalmic, a., 

 -thal'-mik, of or pert, to exoph- 

 thalmia. 



exopodite, n., eks-op'-od-lt (Gr. 

 exo, outside ; pous, a foot, 2 j odos } 



of a foot), in zool., the outer o: 

 the two secondary joints int( 

 which the typical limb of a Crust- 

 acean is divided. 



exorhizal, a., eks'd-riz'al (Gr. exo, 

 outside; rhiza, a root), in bot., 

 applied to those plants whose 

 roots in germination proceed at 

 once from the radicular extremity 

 of the embryo. 



exoskeleton, n., eks'-o-skel'-Zt-dn 

 (Gr. exo, outside ; skeleton, a dry 

 body or skeleton), the external 

 skeleton, constituted by a hard- 

 ening of the integument; also 

 called dermo-skeleton. 



exosmose, n., Zks'-d's-moz, also ex- 

 osmosis, n., 'eks'-d's-moz'-is (Gr. 

 exo, outside ; osmos, a thrusting, 

 an impulsion), the passing out- 

 wards of a fluid through a mem- 

 brane from the inside; the passing 

 inwards from the outside being 

 called endosmose. 



exospore, n., Zks'-o-spor (Gr. exo, 

 outside ; spora, a seed), the outer 

 covering of a spore : exosporous, 

 a., Vks-os'-por-tis, having naked 

 spores, as in fungi. 



Exostemma, n., Zlcs'-O'StZm'-mti 

 (Gr. exo, outside ; stemma, a 

 crown alluding to the exserted 

 stamens), a genus of plants, Ord. 

 Rubiacese, whose species yield 

 various kinds of false cinchona 

 bark, which do not contain the 

 cinchona alkalies : Exostemma 

 floribundum, fl$r<i-bund''iim (L. 



flos, a flower, floris, of a flower ; 

 abundus, abundant), a species 

 described as a timber tree. 



exostome, n., %lcs f '0-stdm (Gr. exo, 

 outside ; stSma, a mouth), in bot. , 

 the outer opening of the foramen 

 of the ovule. 



exostosis, n., &*?#&& (Gr. ex- 

 ostosis, a bony excrescence from 

 exo, outside ; osteon, a bone), an 

 unnatural projection or growth 

 from a bone; a wart-like ex- 

 crescence often seen on the roots 

 of leguminous plants. 



exothecium, n., vks'-o-the'sM-um 



