Plastogamy 



pleuroblastic 



ment of the entire protoplasmic 

 cell-contents, including the nucleus 

 and the chromatophores (Zach- 

 arias) ; Plastog'amy (70^05, mar- 

 riage), the fusion of cytoplasts 

 into a plasmodium, the nuclei 

 remaining distinct (Hartog) ; adj. 

 plastogam'ic ; Plastog'eny (7^0?, 

 race, offspring), when cytoplastic 

 elements undergo a reorganisation 

 by fusion (Hartog) ; Plas'toid 

 (eTSos, likeness), a needle-shaped 

 body found in the stalk -cells of the 

 tentacles of Drosera, becoming 

 rounded under stimulus; a rhab- 

 doid. 

 Plate, a flattened structure; cf. 



NUCLEAR ~, SIEVE ~ . 



Plateau' (Fr.), (1) the tubercular disk 

 in a bulb which produces the 

 scales upwards, and the roots 

 downwards, cf. CORM (Crozier) ; 

 (2) a similar structure in certain 

 Compositae, interposed between 

 the ovary and the other floral 

 organs (Lecoq). 



platycar'pic, platycar'pous (TrXarfo, 

 broad, Kaptrbs, fruit), broad-fruited ; 

 Platylofo'eae (Xo6s, a lobe), used 

 for certain Crucifers with flat coty- 

 ledons ; platylo'bate, broad-lobed ; 

 platyphyl'lous ((ptXXov, a leaf), 

 broad-leaved. 



Plecolep'is, J Plecolep'idus (ir\Kw, I 

 plait, XeTris, a scale), the involucre 

 of Compositae when the bracts 

 are united into a cup. 



Plectench'yma (TrXe/rros, woven, 

 eyxvfM, an infusion), a tissue of 

 woven hyphae ; a pseudo-par- 

 enchyma, further divided into 

 PARAPLECTENCHYMA and PROSO- 

 PLECTENCHYMA (Lindau). 



Pleioblas'tus (TrXetoi', more, /SXaoros, 

 a bud), used by Koerber for those 

 Lichen spores which germinate 

 at several points ; Pleiochas'ium 

 (xdcns, separation), each relative 

 main axis of a cyme producing 

 more than two branches ; adj. 

 pleiocnas'ial ; pleiocy'clic (xtfoXo?, 

 a circle), perennial, as ~ Herbs; 

 Pleiom'ery (/AC/JOS, a part), having 



more whorls than the normal 

 number ; Pleiomor'pnism, Pleio- 

 mor'phy (nop^-fj, change), the oc- 

 currence of more than one inde- 

 pendent form in the life-cycle of 

 a species; Pleiont'ism, Delpino's 

 term for POLYMORPHY ; pleio- 

 phyl'lous, -lus (<f>v\\ov, a leaf), with 

 leaves having no apparent buds 

 in their axils ; Pleiophyl'ly, having 

 numerous leaves from the same 

 point, or more than usual the 

 number of leaflets in a compound 

 leaf; Pleiopyre'nium ( + PYRENIUM), 

 small apothecia in one verruca, in 

 Lichens ; pleiosper'mous ((nrep/j,a, 

 a seed), with an unusually large 

 number of seeds ; Pleiotax'is, Plelo- 

 tax'y (rctis, order), increase in the 

 number of whorls in a flower ; 

 Pleiotrache'ae (+ TRACHEA), 

 "membranous tubes or tracheae 

 containing a compound spiral 

 fibre " (Cooke) ; Pleiox'eny (Zeros, 

 a host or guest), where a parasite 

 can invade several species of host- 

 plants (De Bary). 



ple'nus (Lat.), full, as Flos plenua 

 = a double flower. 



Pleochrolcism (ir\eov, more, x/>oa, 

 colour, complexion), with various 

 colours in the cell- wall ; syn., Pleo- 

 chro'mism (xpwfia, colour), adj. 

 pleochro'ic, pleocnrois'tlc ; Pleo- 

 mor'phism, Pleomor'phy (/to/x^, 

 shape), the same as PLEIOMORPHISM. 



Ple'on, Naegeli's term for an aggre- 

 gate of molecules, but smaller than 

 a MICELLA. 



Ple'onasm (7rXeo^a<r/ia, a surplus), 

 redundance in any part (Crozier). 



Ple'rome (7rX?7pw/Aa, that which fills), 

 the cylinder or shaft of a growing 

 point enclosed and overarched by 

 periblem ; ~ Sheath = BUNDLE- 

 SHEATH. 



plesiomor'phous (7rX?7cr/os, near, fj.op<fy^, 

 shape), nearly of the same form 

 (Crozier). 



Pleu'ra (TrXeu/oA, a side or rib), the gir- 

 dle or hoop of Diatoms (0. Mueller) ; 

 Pleurench'yma (eyxvpa, an infu- 

 sion), woody tissue ; pleuroblas'tic 







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