170 



INDEX AND GLOSSARY 



Penzig, 0., 113 



Pilobolus, a Mucorineous Mould, 

 which grows on dung, 117 



Pinnae, segments of leaves, 33 ; 

 fertile, 65 



Pistil, the central region of the 

 flower, which bears and pro- 

 tects the ovules, 72 



Plankton, a general terra for the 

 floating life of the sea, or of 

 freshwater, 72, 86 



Plant, the, 23, 156 ; immobile, 

 161; movements of, 82, 156 



Plant-life on Land, origin of, 155 



Plant-population, 102 



Pollen, the detachable male spores 

 of Seed-plants, 52, 70, (Fig. 14) 

 71 



Pollen-grain, (Fig. 14) 71 



Pollen-tube, the tube which grows 

 out from the pollen-grain, and 

 traversing the style, conveys 

 the sexual cells or gametes 

 to the ovule, (Fig. 14) 71, 

 (Fig. 15) 73, 74, 77, 156 



Pollen-sac, the chamber in which 

 the pollen-grains are produced. 

 There are usually four of them 

 on each anther, 52, 53, 70 



Pollination, the transfer of pollen 

 from the anther to the re- 

 ceptive surface of the stigma, 

 or, in Gymnosperms, directly to 

 the ovule, 68, 95, 160 



Pollination, difficulty of, 91 ; 

 agents for effecting, 96 



Pollinating mechanisms, 69, 160 



Polygonum convolvulus, a climb- 

 ing Dock, common in corn 

 fields, 73 



Polypodium aureum, a common 

 cultivated Fern, 107 



Population of plants, 102 



Position, fixity of, 81, 87 



Propagation, period of, 19 



Prothallus, the sexual stage, or 

 gametophyte, as in a Fern, 

 (Fig. 7) 39 



Protoplasm, movements of, (Fig. 

 18)85 



Protoplast, the whole body of 

 living protoplasm belonging to 

 a single cell, 18, 19, 84, 99 



Pteridium aquilinum, the Com- 

 mon Bracken, 30 



Pteris aquilina, the older synony- 

 mous name for the Bracken 

 Fern, 30 



Puff-balls, 140 



Babbits, 150 



Race, maintenance of, 97 ; spread 

 of, 97, 161 



Radish (Raphanus), 106 



Raw Material of Golf Course, 

 (Fig. 27) 149, 150 



Receptacle, the enlarged out- 

 growth of the Fern leaf on 

 which the sporangia are in- 

 serted, 37 



Rest Harrow (Ononisspinosa), 142 



Rhizoid, a cellular outgrowth 

 which has an absorptive func- 

 tion, 20, 39 



Rhizome, an underground stem, 

 as in the common Bracken, 

 (Fig. 4) 31, 44 



Roots, attachment of, 87 



Royal Fern (Osmunda regalis), 60 



Rue, Meadow (Thalictrum), 96 



Runners, horizontal underground 

 stems, 132 



Rush (Juncus), 140 



Salt-wort (Salsola), 127, 129, 

 (Fig. 21) 132 



