ex 
Existem 
forms are considered to have been 
evolved from simpler ones. 
ex, privative prefix in place of e, 
when a vowel follows ; exo = out- 
ward. 
exalbu’minous, exalbumino'sus (ex, 
priv., + ALBUMEN), destitute of al- 
bumen, used only of seeds when 
the embryo occupies the whole 
cavity within the testa; ex’alate, 
exala’'tus (alatus, winged), wingless. 
he (Lat., raised high), lofty, 
tall. 
Exanthem’ata (€&, out of, dvdos, a 
flower), blotches on leaves, etc., as 
though eruptive; Exanth’ium { 
bractlets of the last degree, in- 
capable of forming axillary buds, 
and immediately external to the 
flower. 
exan’nulate (ex, priv., annulus, a 
ring), used of Ferns which do not 
possess an elastic ring round their 
sporangia ; exapophysa’tus (+ Aro- 
PHYSIS), destitute of an apophysis, 
or swelling below the capsule of a 
Moss. 
ex’arch (€£, out of, apy, origin), used 
of vascular bundles in which the 
whole primary wood is centripetal, 
almost the same as perixylic. 
exar’eolate, exarcola’tus (ex, priv., + 
AREOLATUS), not spaced out or 
marked into small areas; exar’il- 
late (+ ARILLA), without an aril; 
exar’istate,exarista’'tus (+ ARISTA), 
destitute of awns. 
exas’perate, exaspera'tus (Lat., rough- 
ened), rough with hard projecting 
points. 
excavate (excavatus, hollowed out), 
as though dug out. 
excen'tric, excentric’us (ev, out of, 
centrum, the centre), one-sided, 
out of the centre, abaxial. 
Ex’ciple, Ex’cipule (Crozier), Excip’- 
ulum, Excip'ulus (excipula, a basin), 
wart - like excrescences on the 
thallus of certain Lichens, which 
have a narrow opening; the por- 
tion of thallus which forms the 
rim round the base of apothecia. 
Excitability, Hxcitabil'itas (excitatus, 
roused), the faculty of responding 
to external stimuli. 
excres cent (excrescens, growing out), 
growing in an unnatural way, as a 
wart or other outgrowth ; Exeres’- 
cence, a gnaur or wart on the stem 
of a tree; enation. 
Excre’tion (ex, out of, cretus, sifted), 
(1) the action by which any sub- 
stance is rejected from the organ- 
ism ; (2) the thing itself excreted, 
aS gum, resin, honey, etc.; excur’- 
rent, excur’rens (Lat., running), (1) 
running through to the apex and 
beyond as a mucro; (2) where the 
stem remains central, the other 
parts being regularly disposed 
round it; ~ Vena’tion, in Ferns, 
when the veinlet is directed out- 
wards. 
exendosperm’ous (é£, out, évdov, with- 
in, o7mépua, seed), used of seeds 
which have reserve material stored 
in the embryo. 
exe’sust(Lat., eaten away), applied 
to a surface irregularly sculptured 
as though by corrosion. 
exfo'liate (ec, from, folzwm, a leaf), to 
come away in scales or flakes, as 
the bark of the Plane; Exfolia’- 
tion, peeling off. 
exha’lant (exhalo, I exhale), breathing 
out, as exhalan’tia Va'sat imaginary 
vessels in the epidermis, actually 
the sides of confluent cells; Ex- 
hala‘tion, the function discharged 
by stomata in passing off vapour. 
exig’uous, exig/uus (Lat., scanty), 
small and narrow, mean. 
exi/lis (Lat.), thin, meagre ; lank and 
straight. 
exim'ius (Lat., distinguished), ex- 
cellent for size for beauty. 
exindu’siate, exindusia'tus (ea, priv., 
+ INDUSIATE), without an indu- 
sium, the membrane which covers 
the torus in Ferns. 
Ex’ine = ExTINE. 
Ex/intine (ex, out, + IntTInzE), the 
middle coat of a pollen-grain, that 
which is next the intine. 
Ex'istem (é£, out, iords, a web), the 
** Aussenschicht”’ of Sanio, consist- 
