XEN- 
xenophya (z&n’6fi'4) 7. p/w. {oe xenos, 
stran Foreign 
d in interspaces oO 
certain Sarcodina, or used in forma- 
tion of shells of certain Protozoa 
(zool.). 
xerophilous (zér6fiiliis)a. [Gk. xreros, 
dry; philein, to love.| Able to 
withstand drou ght; appl. plants 
ton fora limited water supply 
erophyte (zéréfit) ~ [Gk. x 
wary: phyton, plant |. "A xerophilous 
plant ; a plant prening in desert 
or uh soil (404. 
xiphihumeralis (zif'thiméri'lis) 1. 
humerus, 
cle extending 
om xiphoid erties to humerus 
anat.). 
xiphip. sea Sat gr nes. n. 
plastron of Chelonia (zoo/.). 
xiphisternum (zi f'istér’niim) nm. [Gk. 
L nu: 
xiphos, sword ; L. sternum, breast- 
bone. he Posterior speiaeat 
rome process of the sternum 
is 
re (zif’oid) a. a rea 
d; etdos, sh pe} d- 
shaped ensiform pee 
xiphoid process,—the oy segment of 
the sternum (amaz); the tail or 
telson of Limulus ooh.) 
[Gk. xiphos, Seca; iylle m, leaf. ] 
Having sword-shaped leaves (4o7.) 
xylem (zilém) 7. [Gk m, wood. | 
The lignified portion of a vascular 
bundle 
xy . [Gk. xylon, 
fruit.| A hard 
» 
“i 
=“ 
i 
sembling wood in structure (07). 
xyloma eo jae * . sylon, 
wood. | se rdened mass of 
mycelium hich gives rise to spore- 
oe structures in certain Fungi 
xylop (ailéfagiis) @. [Gk. 
xylon, wood; phagein, to eat.] 
350 
‘yellow cartil 
YOL- 
Wood-eating ; aff/. certain Mol- 
luscs and Insects (zool.). 
xylostroma (ziléstro’ma) #. ([Gk. © 
xylon, wood ; stroma, couch.] The 
felt- like mycelium of certain wood- 
od ; e 
ae or cut wood (zo0 
¥ 
,—a cartilage in 
which the ae is everywhere 
yellow connective 
probably ex- 
in the — of Turbellarians ; in 
adiolarians, symbiotic algae oO 
Ssschicrellac (zool.). 
resi fibres,—see elastic 
ly naa macula eer B the 
etna (ana ) 
yok) [A.S.. 7 songs, sare 
iow. eat The inert, or no 
forma — nutrient terial in he 
ovu 
votk-duct, —the asin duct (zo0/.). 
yolk - the epithelium 
seen "ie yolk-sac (emb.). 
certain worms b 
furnished with 
material 
appearing in the ovarian egg (cy4.). 
ee oe allel lamellae tote 
which the deutoplasm may be split 
up in exe-yolk of Amphibia and 
many Fishe 
yolk - plug the mass of yolk- -cells 
filling up ‘the blastopore, as in the 
Frog (cy : 
yolk-pyramids,—certain of the cells 
formed in the ao egg 0 
the Brea ica (zool.). 
yolk —a membranous sac at- 
tached to the embryo and contain- 
ing which passes to the 
oo through the vitelline duct, 
and acts as food for the developing 
pasar (emé.). 
