INDEX AND GLOSSARY 



697 



Tetracyclic, of gamopetalous flower 

 with four cycles of parts, 268. 



Tetracycliceae, 641. 



Tetrad, a group of four spores re- 

 sulting from division of one spore- 

 mother-cell, 563 (Fig. 430) ; its 

 relation to Mendelian segregation, 



572. 



Tetrad-division (meiosis) of a spore- 

 mother-cell, first into 2, then into 

 4, forming the tetrad ; reduction 

 of chromosomes accompanies it, 

 285 ; in formation of pollen, 286 

 (Fig. 207) ; in formation of em- 

 bryo-sac, 296 (Fig. 217) ; in 

 sporangia of Higher Plants, 353, 

 563 (Fig. 430, 564). 



Tetramerous, with parts in whorls of 

 four, 265. 



Tetraploid, see Polyploid. 



Tetraspores, of Red Seaweeds, 389 ; 

 of Dictyota, 383, 545 ; of Fungi, 

 401. 



Tetraphis, gemmae of, 466. 



Thalictrum, somatic parthenogenesis 



in, 587- 



Thallophyta, plants with no clear 

 distinction of stem and leaf, 3, 354 

 (Chap, xxi.) ; alternation in, 546. 



Thelephora, part of Lichen, 446. 



Tissues, of stem, 40 (Chap, iv.), of 

 leaf, 69 (Chap, v.) ; of root, 82 

 (Chap, vi.) ; mutual tensions of, 



174 ( Fi g- Io8 ) 

 Tmesipteris, 524. 



Toad-flax, 159 ; zygomorphy of, 274 

 (Fig. 199) ; deposit of seeds, 328. 



Toadstools, 391, 393, 431. 



Tomato, inheritance of fruit-colour, 

 578. 



Tooth-wort, parasitism of, 226. 



Torus of bordered pits, 531 (Fig. 418). 



Toxines, 452. 



Tracheae, a general term including 

 tracheides and vessels. They have 

 woody walls and no cell-contents 

 when mature, 45. 



Tracheide, a cell with complete woody 

 walls and no cell-contents : fibrous, 

 46 (Fig. 24), 59 (Fig. 38) ; of Coni- 

 ferous wood, 530 (Figs. 417-419) ; 

 of Fern, 488 (Figs. 377"379). 



Tragopogon, latex vessels of, 54. 



Transformation theory, 546. 



Translocation of materials, 130. 



Transpiration, exhalation of water- 

 vapour, 99-105 ; transpiration 

 stream, 99, 105 ; path of, 106 (Fig. 

 72) ; stomatal control of, 105 ; 

 significance of, 100 ; measurement 



of, 101 (Fig. 69) ; conveys salts, 



100. 

 Transverse plane, in a floral-diagram 



a plane perpendicular to the median 



plane, 263. 

 Trefoil (Lotus), 635 (Fig. 489). 

 Tremellales, 432. 

 Trichocolea, structure of, 473. 

 Trichodesmium, of ' Red Sea," 



377- 

 Trichogyne, the receptive filament of 



Red Seaweeds, 389 (Fig. 290) ; of 



Fungi, 400, 418 ; of Collema, 429. 



Tricoccae, 628. 



Trimerous, with parts in whorls of 

 three, 263 (Fig. 187), 265. 



Triticum repens, vegetative propa- 

 gation of, 252. 



Triticum vulgare, analysis of, 660 ; 

 origin of, 661. 



Tropaeolum, structure of lamina, 75 

 (Fig. 49) ; exudation of water from 

 leaf, 109 (Fig. 74, A). 



Tropic responses, 154. 



Truffle (Tuber), 401, 418, 426 (Fig. 



325)- 

 Tubercle Bacillus, 451. 



Tubercles (Nodules), on Leguminous 

 roots, 235 ; fixation of nitrogen in, 

 236-237. 



Tuberous stems, 177. 



Tubers of Nephrolepis, vascular sys- 

 tem of, 598 (Fig. 454). 



Tubuliflorae, 649. 



Tulip, chromoplasts in petals, 280 ; 

 flower of, 607. 



Turgor (turgescence), the tense con- 

 dition of living cells owing to pres- 

 sure of the protoplast on the wall, 

 34, 38 ; of stoma, 100, 103 (Figs. 

 70, 71) ; rigidity based on, 170. 



Turnip (Brassica), analysis of, 655 ; 

 origin of, 654. 



Twining stem, 215 (Fig. 144) 



Ulotrichales, 361, 365, 375. 

 Ulothrix, 365 (Fig. 270), 368, 547. 

 Ulva, 365. 



Ulvaceae, 361 ; isomorphic alterna- 

 tion in, 390. 

 Umbellales, 637 (Fig. 490)- 

 Umbelliferae, fruit of, 323 ; flower of, 



637- 

 Unilocular sporangia, 381. 



Uredinales, 397, 401, 431 (Figs. 329- 

 338) ; life-history of, 432. 



Uredospores (or summer-buds, or 

 spores of Puccinia), 432 (Fig. 331) ; 

 germination of, 434 (Figs. 332, 333). 



