Politropism 
Pollinarium 
circulating portion ot the eyto- 
plasm. 
Polit’ropism = PoLyTROPIsM. 
poli’tus (Lat.), polished. 
pollachig’enus (7roAAax%, often, yervdw, 
I bring forth) =PoLycarric. 
Pol’len (Lat. fine flour), (1) the ferti- 
lising dust-like powder produced 
by the anthers of Phanerogams, 
more or less globular in shape, 
sometimes spoken of as ‘‘ Micro- 
spores”; (2) the antherozoids of 
Mosses (Hooker and Taylor); ~ 
Carrier, the retinaculum of Ascle- 
piads, the gland to which the 
pollen-masses are attached, either 
immediately or by caudicles; ~ 
Cells, cavities of the anthers in 
which pollen is formed ; ~ Cha’m- 
ber, (1) a cavity at the apex of 
some ovules beneath the integu- 
ments in which the pollen-grains 
lie after pollination, as in Cycas; 
(2) the extine of the pollen in 
some Coniferae dilated into two 
hollow expansions to facilitate 
dispersion by wind; ~ Grain, 
Gran’ule, the small bodies which 
compose the entire mass; the 
latter term is also used for the 
contents of the grain; ~ Mass, 
pollen-grains cohering by a waxy 
texture or fine threads into a single 
body; ~ Sac, the micro-sporangium 
in Phanerogams; ~ Spore = ~ 
Grain; ~ Tet/rad, the shape of 
certain groups consisting of four 
grains cohering in a pyramid, as 
in Oenothera; ~ Tetrahed’ron= last; 
~ Tube, the tube emitted by a 
pollen grain passing down from 
the stigma to the ovary and 
ovules.—The various markings of 
the pollen-grains in Acanthaceae 
have received special names from 
L. Radlkofer and G. Lindau, 
which have been used in their 
original form in the ‘‘Flora of 
Tropical Africa”; the following 
account of them may be useful: 
Dau'ben ~ (Stave ~) a modifica- 
tion of Schalen- or Spalten ~, with 
broadened fissures having a stave- 
203 
like insertion ; Do’sen ~ (Box ~), 
elliptic, with three longitudinal 
stripes and a pore in each; Facet- 
tier’ter ~ (Facet ~), with facetted 
surface ; Fal’ten ~ (Fold ~), with 
smooth surface and three deep 
longitudinal grooves; Glat’ter ~ 
(Smooth ~ ), destitute of prominent 
markings; Giir'tel ~ (Girdle ~), 
having a zone of varied marking ; 
Kam’mrad ~ (Cogwheel ~), having 
regular projections on the equa- 
torial region ; Knét’chen ~, an 
abbreviation for Knétchendo’sen 
~,(Nodule ~), having a tuberculate 
surface ; Lin’sen ~ (Lens ~), 
doubly convex in form; Rah’men 
~ (Frame ~), with six small and 
three broad streaks between the 
poles; Rip’pen ~ (Rib ~), with 
longitudinal ribs having punctate 
markings on them; Run’der ~ 
(Round ~) spherical in form ~; 
Scha’len ~ (Shell ~ ), with three slits 
which do not reach the poles, and 
without pores, the pollen-tubes 
emerging from the slits, cf. SpaL- 
TEN ~; Spal’ten ~ (Fissure ~), 
with three longitudinal fissures, 
sometimes with pores in them ; ¢f. 
ScHALEN ~ ; Span’gen ~ (Clasp 
~), main ribs three, smaller ribs 
six, with three pores in the equa- 
torial region, one between each 
two of the smaller ribs ; Sta’chel ~ 
(Spine ~), having a _ spiny 
surface, pores from three to 
many ; Wa'ben ~ (Honey-comb 
~), having an areolate surface ; 
pol’lenate, to fertilise by pollen; 
Pollena’tion = POLLINATION ; pol- 
leniforous, -rus (fero, I bear), 
poullen-bearing; Pol'lenine, the con- 
tents of pollen-grains ; Pol’lenoid = 
PouurinorD. 
Pol’lex (Lat., a thumb), an inch in 
length, nearly 25 mm. 
poliica’ris (Lat., pertaining to a 
thumb), an inch in length, about the 
length of the end joint of the thumb. 
Pollina’rium, pl. Pollina’ria (Pollen, 
fine flour), (1) = ANDROECIUM ; (2) 
= CYSsTIDIUM. 
