inuncans 
Irritability 
inun‘cans +} (Lat., hooking),the surface 
covered with glochidia or hooked 
hairs. 
inunda’tal (inundatus, overflowed), 
Watson’s expression for those 
plants which grow in places liable 
to be inundated in wet weather, 
but dry in summer; inunda’tus, 
flooded, sometimes under water, 
sometimes dry. 
-inus, a Latin suffix, meaning, (1) 
resemblance ; (2) augmentation. 
invag’inated (in, into; vagina, a 
sheath), enclosed in a sheath. 
inverse’ (inversus, turned about), in- 
verted ; Inver’sion, (1) a change of 
order or place; the action of In- 
vertase ; (2) In’vert- en’zyme, In’- 
vertase, an unorganised ferment, 
which transmutes cane-sugar into 
inverted-sugar ; inver’ted, having 
the apex in an opposite direction 
to the normal ; Inver'ted-su’gar, u 
mixture of fructose and glucose by 
the action of invertase on cane- 
sugar ; ~ Superposit’ion, the position 
of accessory buds below the princi- 
pal bud, or one first formed (Crozier); 
inver’tens (Lat.), inverting, becom- 
ing reversed, as inverten’tia Fo'lia, 
leaves which in sleep hang down- 
ward, but touch by the upper sur- 
face, as in Cassia; In’vertin= 
InvERTASE; this form is chiefly 
employed by zoologists, 
invisible (invisib’ilis, not to be seen), 
used of any organ which is not 
sufficiently developed to be seen, 
vol’ucel, Znvolucel’lum (Fr., involu- 
celle, from involucrum, a wrapper), 
a secondary partial involucre; 
involucel’late, involucelia’tus, pro- 
vided with a secondary involucre ; 
involu’cral, involucra‘lis, belonging 
to an involucre; Invol’ucrate, In- 
volucra’tus ; involu’cred, having an 
involucre of some kind ; Involu’cre, 
Involu'crum, (1) a ring of bracts 
surrounding several flowers or their 
supports, as in the heads of Compo- 
sites, or the umbels of Umbelli- 
ferae ; (2) the tissue of the thallus 
in Anthoceroteae, grown up and 
overarching the embryo, afterwards 
pierced by the lengthening sporo- 
gonium; (3) the peridium, volva 
or annulus in Fungi (Lindley) ; (4) 
the indusium of Ferns; gen’eral~, 
that which is at the base of a com- 
pound umbel; par’tial ~, secondary 
~, that which surrounds a partial 
umbel; involu'cra Lig’nea, Mal- 
pighi’s name for the concentric 
zones of growth in exogens; In- 
volu’cret, an involucel. 
in'volute, involu’tus, involuti’vus 
(Lat., enwrapped), having the 
edges of the leaves rolled inwards ; 
Involu‘tion, (1) the act of rolling 
inward ; (2) the return of an organ 
or tissue to its original state ;~ 
Form, a swollen bladder-like form 
of Schizomycetes, supposed to be 
a diseased condition of the form 
associated with it; ~ Pe’riod, the 
resting period ; ~ Spore, a rest- 
ing-spore ; ~ Stage, the resting 
stage. 
invol’vens (Lat.), rolling together, as 
involven'tia Fo'lia used by De Can- 
dolle, for trifoliate leaves whose 
leaflets rise up, unite at the summit 
. . . 80 as to form an arch which 
shelters the flowers, as in Trifolium 
incarnatum, Linn. (Lindley). 
io’des (dys, violet-coloured), iodi’nus, 
violet ; I’odine, an elementary body 
obtained from marine Algae, etc.; 
io’nides, violet-coloured. 
irreg’ular, irregula’ris (Late Lat. , not 
according to rule), (1) wanting in 
regularity of form; (2) asymmetric, 
as a flower which cannot be halved 
in any plane, or one which is 
capable of bisection in one plane 
only, zygomorphic; ~ Pelor‘ia, 
a monstrosity by which irregular 
form has become regular by sym- 
metric development ; Irregular’ity, 
Trreguiar'itas, the state of being 
unequal in form. 
Irritability (irritabilis, easily ex- 
cited), phenomena induced by 
stimuli, such as shock, absence 
or presence of light, warmth, 
gravity, etc. 
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