562 



BOTANY OF THE LIVING PLANT 



Herbaceous Dicotyledons, stem of, 35. 



Hereditary transmission, a conse- 

 quence of sex, 462. 



Heredity, 461 (Chap. xxxi.). 



Hermaphrodite, where male and 

 female organs are on the same 

 individual : applied to flowers 

 when they contain both stamens 

 and carpels, 222, 265. 



Heterocysts. of certain Cyanophyceae, 



457- 



Heteroecism, where the life-cycle 

 of a parasite is completed by 

 stages on distinct hosts, 422. 



Heterosporous, applied to vascular 

 plants in which there are distinct 

 megaspores and microspores, 325, 

 351 ; a derivative state, 486 ; 

 adoption by Pteridophytes and 

 seed-plants, 489. 



Heterothallic, in Mucorini, where 

 zygospores are onl}^ produced on 

 meeting of branches of two differ- 

 ent mycelia, 426 (Fig. 361). 



Heterotrophic, applied to nutrition 

 by some accessory or irregular 

 method, in addition to, or even 

 superseding self-nutrition, 187 

 (Chap. xi.). 



Heterotype division, another name 

 for Reduction-division : conveying 

 the fact that the resulting nuclei 

 are of a type different from their 

 predecessors, 468, 469. 



Heterozygote, formed by union of 

 two dissimilar gametes, 475, 476. 



Hieracium, somatic parthenogenesis 

 in, 477. 



Hilum, scar of attachment of a seed 

 to the parent plant.. 6. 



Himanthalia, 385. 



Hip, of Rose, a succulent hollow 

 receptacle, 293. 



Hippuris, jNIare's tail, 16, 17 (Figs. 

 7, 8), 36, 40. 



Hofmann's apparatus, 103 (Fig. 76). 



Holly, indurated leaf -margin of, 158. 



Homologous alternation, 479, 481. 



Homoplastic development, 160. 



Homoplas}^ where similar morpho- 

 logical results are produced by 

 adaptation in two or more distinct 

 evolutionary lines : of parasites, 

 193 ; in Algae, 401. 



Homosporous, applied to archegoni- 

 ate plants in which there is only 

 one type of spore, 325, 351 ; a 



primitive state, 485, 487 ; fulh' 

 exploited in Pteridophytes, 489. 



Homothallic, in Mucorini, where 

 zygospores are produced on meet- 

 ing of two branches of the same 

 mycelium, 426. 



Homotype-division, the second divi- 

 sion in the spore-tetrad, carried 

 out like any somatic di\dsion. 

 466, 469. 



Homozygote, formed by union of 

 two gametes similar in respect of a 

 given character, or characters, 



^^ 475 (Fig. 396). 



" Honey Dew," 406 (Fig. 341) ; 436 

 (Fig. 369). 



Honey Agaric, parasitism of, 404 

 (Fig. 340); 411 (Fig. 347). 



Hooks, in seed dispersal, 292 (Fig. 

 238). 



Hop, twining stem of, 182. 



Hop-mildew (Sphaerotheca), 431. 



Hordeum (Barley) analysis of, 547 ; 

 origin of, 548. 



Horse-chestnut (Aesculus), 13 (Fig. 6); 

 69 (Fig. 52). 



Horse-tail, vegetative propagation of, 

 218, 316. 



Host, a plant or animal that supplies 

 food to a parasite, 187. 



Hottonia, 10 1. 



Humble-bee, agent for pollination of 

 Aconite, 266. 



Humus, leaf-mould, decaying vege- 

 table matter of the soil, 188. 



Hura (Sand-box Tree), explosive fruit 

 of, 133 (Fig. 94) ; dehiscence of 

 fruit, 287, 516. 



Hyacinth, qualities of fibres of, 146; 

 perennation of, 165 (Fig. 125). 



Hybridisation, the result of crossing 

 of more or less dissimilar parents, 

 470. 



Hydrom, water-conducting tissue of 

 Mosses, 357 (Fig. 299). 370. 



Hydrophytes, plants adapted to life 

 in presence of plentiful water, 175, 

 178. 



Hydrotropism, response to stimulus 

 of unequal water-supply, 128 ; 

 positive, of pollen-tubes, 268. 



Hygroscopic movements, due to 

 changes in degree of moisture, 

 133 (Figs. 93, 94, 95) ; of seeds and 

 fruits, 297. 



Hymenial gonidia, Algal cells in the 

 hymenium of a Lichen, 440. 



