Pottia’ceous (SUPPLEMENT) Prosoplasm 
pottia’ceous, allied to Pottia. 
Prae’form (+ Form), an early form, 
the original ancestral strain 
(Kuntze); Praemuta’tion (+ Murta- 
TION) ; the inner preparation of a 
plant, for the outward manifesta- 
tion = Mutation (De Vries). 
Presenta'tion Time, the period re- 
quired for an organ to take up 
perception (Macdougal). 
Pre-bract’eole, the sub-sporal bract 
in Chara; it may be restricted to 
a single swollen cell (Allen). 
Primule’tum, Clements’s term for an 
association of Primula. 
prismat’ic Lay’er, Farmer’s term for 
a layer of cells in Jsoétes sur- 
rounding the xylem cylinder 
(Campbell). 
Proces’sus, see Banps, in fruit of 
Zostera minor. 
Prochro’matin (+ CHRromamTiIN), the 
substance of nucleoli (Pfitzner). 
Prochys’ium (mpéxvois, a pouring 
out), succession of plants on allu- 
vial soils (Clements), published as 
“¢ Prochrosium.” 
Prod’romus (Lat., a forerunner), fre- 
quently employed in botanic works, 
which are intended should be 
followed by more complete treatises. 
Progameta'tion (+ GAMETE), em- 
ployed by Maire to denote the 
act of synkaryons becoming pro- 
gametes ; Progame’tophyte (¢uroy, 
a plant), the plant which produces 
progametes (Maire); Progemma’- 
tion (+ GrMMaTIon), when stylo- 
spores are given off from basidia, 
new terminal cells being developed 
from older or basal cells (Nylander); 
progeoesthet‘ic (yf, earth, alc- 
Onrixos, perceptible), applied to the 
root-tip when tending downwards ; 
Prohydrotrop’ism (+ Hypro- 
TROPISM), turning towards a source 
of moisture (Macdougal); adj. 
prohydrotrop’ic; Prokaryogam’ete 
(kdpvov, a nut, = nucleus, ydpos, 
marriage), the nucleus of a primary 
progamete (Maire); Prokarygame- 
tisa’tion, quantitative reduction 
(Maire), 
prolep’tic, anticipatory. 
prolific Cells, reproductive cells 
(Wittrock); prolifi'ed, grown out 
into prolification, as a tuft of 
leaves from a cone. 
prometatrop’ic (uéra, from, tporh, 
a turning), in crossing, when the 
interchange is between the plants, 
the pollen of one going to the other, 
but the pollen not from anthers 
associated with the ovaries ferti- 
lized (K. Pearson); promyce’lial, 
relating to a promycelium; ~ 
Spores, those generated in asci 
(Cooke) ; the Sporidia of continental 
mycologists (Plowright). 
Proodophy’tia (rpdodos, in advance, 
guror, a plant), initial plant forma- 
tions (Clements). 
prop’er Valves = SPATHE-VALVES. 
prophototac’tic (raxrixds, arranging), 
turning towards light (Macdougal); 
the condition itself is Prophoto- 
tax’is; Prophototrop’ism (rpori, 
turning), moving towards thecentre 
of the radiating light (Macdougal) ; 
Pro’phyll, bracteole, cf. Pro- 
PHYLLUM, 
pros- (pos, towards), employed to 
denote positive phenomena by 
Rothert, as in the following :— 
Prosaérotax’is (+ AzRoraxis), the 
stimulus of oxygen on the move- 
ment of zoospores and other motile 
organisms; Proschemotax‘is (+ 
CHEMOTAXIS) attraction by cer- 
tain substances, shown by bac- 
teria, antherozoids, etc.; adj. 
proschemotac’tic ; proschairlim- 
netic (xalpw, I rejoice, Arn, 
a pool), occasionally belong- 
ing to Limnoplankton (Forel); 
Prosgalvanotax is = GALVANOTAXIS; 
prosgeotrop‘ic (+GEoTRorIc), the 
positive influence of gravity on 
organs during growth; the con- 
dition is Prosgeot’ropism; pros- 
heliotropic (+ HELIOTROPIC), turn- 
ing towards the source of light; 
the state is Prosheliot’ropism ; 
Proshydrotax’is (+ HypRoraxis), 
negative osmotaxis; Pro’soplasm 
(whdopa, moulded), used of patho- 
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