Politropism 



Pollinarium 



circulating portion ot the cyto- 

 plasm. 



Polit'ropism = POLYTROPISM. 



poli'tus (Lat.), polished. 



pollachig'enus (-rroXXaxrj, often, yevvdw, 

 I bring forth ) = POLYCARPIC. 



Pollen (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 Ta}'lor) ; ~ 

 Carr'ier, 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 ; ~ Tetrahedron = 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. Lindan, 

 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- 



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 ; Knot'chen ~, an 

 abbreviation for Knbtchendo'sen 

 ~, (Nodule ~), having a tubereulate 

 surface ; Lin'sen ~ (Lens ~ ), 

 doubly convex in form ; Kah'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 ; cf. 

 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- 

 leniferous, -rus (fero, I bear), 

 pollen -bearing; Pol'lenine, the con- 

 tents of pollen-grains ; Pol'lenoid = 



POLLINOID. 



Pol'lex (Lat., a thumb), an inch in 



length, nearly 25 mm. 

 pollica'ris (Lat., pertaining to a 



thumb), an inch in length, about the 



length of the end joint of the thumb. 

 Pollina'rium, pi. Pollina'ria (Pollen, 



fine flour), (1) ANDROECIUM ; (2) 



= CYSTIDIUM. 



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