OrUioblast 



OsteoBclereidi 



Or'thoblast (opfl^s, upright ; BXaarhs, a 

 bud), used by Cramer for confer- 

 void prothallia growing iu an 

 ascending direction ; orthoclad'ous, 

 -dies {K\ddos, a branch), straight 

 branched (Russow) ; Orthen'oliyma 

 {iyxeo, I pour in), Williamson's cor- 

 rection of Orthosen'ohyma, Binnev's 

 term for parenchyma of vertically 

 arranged cells ; adj. orthen'ohymous ; 

 Orthogen'esis (yeVeo-ts, beginning), 

 development along definite lines ; 

 orthoheliotrop'io (-f heliotropic), 

 directed straight to the source of 

 light, as linear leaves and grasses 

 may do ; orthomor'phous {ij.op<p7}, 

 shape), radial and erect (Wiesner) ; 

 Orthophototax'y {<pvs, farhs, light ; 

 rd^is, order), the direct arrange- 

 ment of such organisms as Volvox 

 and Sfirogyra assume under the 

 stimulus of light (Oltmanns) ; or- 

 thophototrop'lo (rpoir)), a turning), 

 the direct influence of light shown in 

 Vaucheria, Phycomyces, and shoots 

 of flowering plants (Oltmanna) ; 

 Or'thophyte {(pvThv, a plant), Janet's 

 term for a plant, the gametophyte 

 -f sporophyte ; Orthoploc'eae (ttAo/c^, 

 a twining), ' those Cruciferae which 

 have conduplicate cotyledons ; ortho- 

 plo'oeous, -ceiis, when the incumbent 

 cotyledons are folded round the radi- 

 cle ; Orthosper'meae {ciripfia, a seed), 

 plants whose seeds have albumen flat 

 on the inner face, neither involute nor 

 convolute ; orthosper'moTui {a"K4pfia, 

 a seed), having seeds with endosperm 

 grooved on the ventral side, as 

 m Carum ; orthostich'otis, straight 

 ranked; Or'thostichy, pi. Or'thos- 

 tiohies {arlxos, a row), a vertical 

 row, as in phyllotaxis ; orthos'- 

 tomons (<rr6iJLa, a mouth), with a 

 straight opening; orthotac'tic {oKrhs, 

 aiTanged), used by S. Moore in the 

 sense of normal, applied to an interval 

 in the Photrum; orthot'ropal, or- 

 thot' ropotiB {rpoirh, a turning), used 

 of an ovule with a straight axis, the 

 ohalaza being at the insertion and 

 the orifice or foramen at the oppo- 

 site end, farthest from the hilum; 



orthotrop'io, assuming a vertical 

 position ; Orthofropism is the con- 

 dition described ; Or'thotype (tuitot, 

 a type), a genus provided with a type 

 by original designation (0. F. Cook) ; 

 adj. orthotyp'ic. 



Oryg'oma {opvy/ia, a ditch or pit), 

 Necker's term for the cup of a 

 Marchantia containing gemmae. 



Os, Or'is (Lat.), a mouth or orifice. 



os'cillating = versatile ; oscilla'nus, 

 oscillator' ius (Lat., from oscillo, I 

 swing), has the same meaning ; 

 Oscilla'tion, the movement peculiar 

 to Trichobacteria and Cyiinopliyceae 

 (Jones). 



osoillatoria'eeoiLS, allied to the genus 

 Osdllatoria. 



Os'culnm (Lat., a little mouth) =« 



OSTIOLR. 



Osmom'eter {wffixbs, a thrusting; 

 fierpov, a measure), an instrument 

 to measure Osmosis ; Os'mose, 

 Osmo'sis, the diffusion of liquids 

 through membranes ; Nu'clear 

 Osmo'sis, the increased size of a 

 nucleus, attributed to absorption of 

 fluid through the nuclear membrane 

 (Anstruther) ; adj. osmo'tic. 



Os'mospores (oo-/*);, scent ; + Spore), 

 certain Uredineous spermagones, 

 characterized by their having a scent 

 (Vuillemin). 



Osmotax'is (ixrixhs, a thrusting; ri-lis, 

 arrangement), rearrangement of mov- 

 ing organisms in response to the 

 influence of fluids; adj.osmotac'tic; 

 Osmot'ropism (rpoir)), a tmning), 

 tropic stimulus due to osmotic action 

 (Pfeffer); adj. osmotroplc. 



os'seous, os'seus (Lat.), bony. 



Ossic^ulus, Ossic'ulum (Lat., a little 

 bone), the pyrene of a fruit, as a 

 medlar. 



os'sified {os, ossis, a bone; facio, I 

 make), becoming hard as bone, as 

 the stones of orupes, such as the 

 peach and plum. 



Ostariphy'tam {oardpioy, a little bone ; 

 <pvrhy, a plant), a plant which 

 produces a drupe or drupe - like 

 fruit. 



Osteosole'reids {hcriov, a bone; <rKAT7/>^5,. 



260 



