Invasion 



isadelphons 



Inva'sion, (iyivasus), an intrusion of 

 an alien plant into regions or 

 stations foreign to it. 



inverse' {inversus, tiu'ned about), in- 

 verted ; Inver'sion, (1) a change of 

 Older or place ; (2) the action of In- 

 vertase ; In'vert-en'zyme, In'ver- 

 tase, an unorganized ferment, wliich 

 transmutes cane-sugar into inverted- 

 sugar ; inver'ted, having the apex 

 in an opposite direction to the 

 normal ; Inver'ted-sugar, a mixture 

 -of fructose and glucose by the 

 action of invertase on cane-sugar ; 

 '- Superposit'ion, the position of 

 accessory buds below the principal 

 bud, or one first formed (Crozier) ; 

 invcr'tens (Lat.), inverting, becom- 

 ing reversed, as iriverten'tia Fo'lia, 

 leaves which in sleep hang down- 

 ward, but touch by the upper sur- 

 face, as in Cassia ; In'vertin = 

 Invertask ; this form is chiefly 

 employed by zoologists. 



invisible {irivisib'ilis, not to be seen), 

 used of any organ which is not 

 sufficiently developed to be seen ; In- 

 vol'ucel, Invoiucel'luvi (Fr., involu- 

 celle, from involucrum, a wrapper), 

 a secondary partial involucre ; 

 involuceriate, invohicella'tus, pro- 

 vided with a secondary involucre ; 

 involu'cral, involucra'lis^ belonging 

 to an involucre ; invorucrate, in- 

 voluera'tus, involn'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 Urabelli- 

 ferae ; (2) the tissue of the thallus 

 in Anthoceroteae, grown up and 

 overarching the embryo, afterwards 

 pierced by the lengthening sporo- 

 gonium ; (3) the pcridium, volva or 

 annulus in Fungi (Lindley) ; (4) the 

 indusium of Ferns ; gen'eral — , that 

 which is at the base of a compound 

 umbel ; par'tial '^ , sec'cndary '^ , 

 thatwhich surrounds a partial umbel ; 

 Invohi'cra lig^nea, Malpighi's name 

 for the concentric zones of growth in 

 exogens ; Involu'oret, an involucel. 



in'volute, involu'tus, involuti'vns 

 (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, tho resting 

 stage. 



invol'vens (T.at.), rolling together, as 

 xnvolven'iia Fo'lia used by A. P. de 

 CandoUe, for trifoliate leaves whose 

 leaflets rise up, unite at the summit 

 ... so as to form an arch which 

 shelters the flowers, as in Trifolium 

 incarnatum, Linn. (Lindley). 



io'des (iw57?s, violet-coloured), icdi'nus, 

 violet ; I'odine, an elementary body 

 obtained from marine Algae, etc.; 

 io'nides, violet-coloured. 



I'on [ihp, neut. of twj/, past part, of 

 fiui. I go), a physical term, defined 

 by J. F. Clark as the division of a 

 molecule ; adj. io'nic ; loniza'tion, 

 the partitioning of a molecule ; 

 ioni'zed, divided into ions. 



I'ridile (+ ile), a society of Iris 

 (Clem.ents). 



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, zygo- 

 morphic ; -^ Pelorla, a monstrosity 

 by which irregular forni has become 

 regular by symmetric development; 

 Irregular'ity, Irregular' itas, the 

 state of being unequal in form. 



Irritabirity {irritahilis, easily excited), 

 phenomena induced by stimuli, such 

 as shock, absence or presence of 

 light, warmth, gravity, etc. 



is'abelline, isahelli'mis (Mod. Lat.,: 

 refers to Isabella, Queen of Spain), 

 a greyish drab colour, a dirty tawny 

 tint. 



isadelph'ous, -its (Jftros, equal to; 

 a^fK<phs, a brother), equal brother- 



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