572 



BOTANY OF THE LIVING PLANT 



Pteridosperms, 326. 



Pteris, root apex of, 276, 335 ; P. 

 cretica, apospory in, 349 (Fig. 293). 



Puccinia graminis (Rust of Wheat), 

 409, 443 (Figs. 375, etc.). 



Puccinia caricis, 444. 



Puff-balls, 441. 



Pulpy-fruits, 293. 



Pyrenomycetes, 437, 439. 



Pyrus malus (Apple), 518, 520 (Fig. 

 426, A). 



Pythium, attack on cress-seedling, 

 413 (Fig. 348) ; hyphae of, travers- 

 ing host-plant, 414 (Figs. 349, 350) ; 

 zoosporangia of, 415 (Fig. 351) ; 

 oospores of, 409 (Fig. 344), 416 ; 

 fertilising tube of, 455. 



Quercus (Oak), 69. 



Quillaija, floral-construction of, 232. 



Quince, flower of, 220 (Fig. 168), 



254 (Fig. 202) ; stigma of, 255. 

 Quotient, respiratory, 141. 



Raceme, an indefinite inflorescence in 



which each pedicel bears one flower, 



226 (Fig. 173). 

 Racial characters, kept pure by 



Mendelian segregation, 476. 

 Radial construction of stele, as seen 



in roots with protoxylem external, 



and alternating wood and bast, 74 



(Figs. 55, 56). 

 Radial symmetry, where an organ or 



shoot develops equally all round, 



168. 



Radicle, first shoot of the embryo, 7. 

 Rafflesia, parasitism of, 193 (Figs. 145, 



146) ; flower of, 194 ; numerous 



seeds of, 210. 



Ragged Robin, 507 (Fig. 412). 

 Raisin, analysis of, 544. 

 Ranunculaceae, 509 (Figs. 414, 417). 

 Ranunculus, 510 (Fig. 416). 

 Raspberry, 521 (Fig. 430) ; analysis 



of, 544- 



Ray-florets, of Compositae, 535 (Fig. 

 442). 



Reaction, change consequent on 

 stimulus, 8. 



Receptacle, the dilated floral axis 

 on which the parts of the flower 

 are inserted, 220 ; various de- 

 velopment of, 237 (Figs. 185-187) ; 

 general receptacle of capitulum, 



227 (Fig. 177) ; arrangement of 

 parts upon, 230 ; succulent, of 

 strawberry, 293 (Fig. 241) ; of 

 sorus in Ferns, 337. 



Recessive, as in dwarf-habit of Peas, 

 473 (Fig. 395). 



" Red-Sea," Algal origin of name, 



457- 



Reduction, a nuclear change by which 

 the number of chromosomes is 

 halved, 251, 468. 



Reduction-division, the first division 

 in the spore-mother-cell by which 

 the number of chromosomes is 

 reduced to one half, 468 ; its 

 relation to Mendelian segregation, 



475- 



Reseda, lateral roots of, 79 (Fig. 62). 



Resetter, a Scots Law term for a 

 receiver of stolen goods, physio- 

 logical resetter, 197. 



Resin passages, of Coniferae, 305. 



Respiration, 112, demonstration of, 

 113 (Fig. 82) ; rise of temperature 

 in, 114; intra-molecular, 115; a 

 means of liberating energy, 115. 



Respiratory-quotient, 114. 



Rest, period of, 297. 



Resupinate, of flower rotation through 

 half a circle so that posterior side 

 appears anterior ; in Orchis, 498. 



Reticulate venation, of leaf of Dicoty- 

 ledon, 60 (Fig. 43). 



Rhea, fibres of, 145. 



Rhinanthus, haustoria in ovule, 280 

 (Fig. 222). 



Rhizobium, fixation of nitrogen by, 



459- 



Rhizoctonia, a mycorhizic Fungus, 



199. 



Rhizoids, of Mosses, 355 (Fig. 296). 

 Rhizome, of Neottia, 202 ; of Ferns, 



328. 

 Rhizomorphs, root-like sclerotia of 



Armillaria, parasitic, 203. 

 Rhizophores, root-bearing organs of 



Selaginella, 318. 

 Rhizopus, 426. 



Rhododendron, evergreen, 162 ; leaf- 

 arrangement, 171 (Fig. 129) ; 



pollen-tubes in style of, 269 (Fig. 



214). 



Rhodomela, 403 (Fig. 339). 

 Rhodophyceae, 372, 3^7 ; alternation 



in, 389, Chap, xxxii. 

 Rhoeadales, 493, 511. 

 Rhopalodia, 481. 



