INDEX 
sporangium, development of, 22; spore- 
mother-cells of, 23; spore tetrads of, 23; 
sexual organs of, 27 ; antheridium of, 27; 
spermatozoids of, 28 ; archegonium of, 28; 
fertilisation of, 29; embryo of, 30, 31; 
life cycle of, 32 (Fig. 16). 
Fern leaf, origin of, 630, 631 ; differentiation 
of, 631. 
Ferns, resistance to drought, 18; vegetative 
propagation of, 19. 
Fern spores, dispersion of, 24. 
Fertile and sterile regions, their relations, 
156, 251. 
Fertile spike of Ophioglossaceae, general 
morphology of, 432-447, 480 ; development 
of, 447, etc. 
Filicales, 495 ; general comparison of, 624; 
external characters of, 625; spore-pro- 
ducing members of, 632; sporangium of, 
637; anatomy of, 646; embryology of; 
649; phylogeny of, 652; essentially 
strobiloid, 657 ; of strobiloid origin, 715. 
Filmy Ferns, classification of, 585; structural 
specialisation of, 586; reduction of spor- 
angia of, 587. 
Fission of spike in Ophioglossaceae, 479. 
Florideae, 67. 
Flower, symmetry of, 207. 
Foliar trace, disintegration of, 668. 
Foot, 672; intra-prothallial of Lycopodium, 
225; in Lycopods, 348; in Selaginella, 
356. 
Formative regions of Hanstein, 178. 
Free-living sporophyte, establishment of, 218. 
Frullania, 264 (Fig. 124). 
Fucus, 66. 
Funaria, 278 (Figs. 136, 137); symmetry 
of, 204 (Fig. 103); Aygrometrica, 91. 
Fungi, alternation in, 68. 
Gametophyte, 32. 
Gametophytic budding, 27, 61. 
General comparison of Filicales, 624. 
Geographical distribution, 5. 
Geothallus, 263. 
Germinal layers, theory of, 175. 
Germs, distribution of, 1. 
Gleicheniaceae, phyletic position of, 654 
(Fig. 354); external characters, 553; spore- 
producing members, 555; anatomy, 561 ; 
spore-enumerations, 559. 
Gleichenia, 553; ctrctnata, 555 (Fig. 310), 
557; spore-enumerations, 559; acarpa 
22 
421 
(Fig. 98); anatomy, 563 (Fig. 314); @icho- 
toma (Figs. 63, 64), 554 (Fig. 310), 557 
(Fig. 311); anatomy, 561 (Fig. 313); 
circinata (Figs. 63, 64); flabellata (Fig. 
64), 554 (Fig. 309), 557 (Fig. 311); 
anatomy, 561 (Fig. 313); @ central 
type, 5643 pectimata, 554; anatomy, 561 
(Fig. 313) 
Glossopteris, 625. 
Gradatae, 117, 497, 498, 470, 634; transition 
to Mixtae, 602. 
Grammatopteris Rigolloti, 498 (Fig. 269), 
501, $32, 539- 
Gnetum gneimon, 97. 
Gunnera polystely, 192. 
Gymnosperms, early existence of, 228, 
Gymnosporangium, 69. 
Hairs of Ferns, 632. 
Haploid phase, 48, 52. 
Hawlea Miltoni, 522 (Fig. 289). 
Haustoria, 181, 672. 
Haustorium, intra-prothallial, 347. 
Helminthostachys, 151 (Fig. 83), 443 (Figs. 
243, 244); external characters, 443 (Figs. 
243, 244) ; spore-producing members, 455 
(Figs. 254, 255); anatomy, 458, etc. (Fig. 
256); embryo, 473 (Fig. 267). 
Hepaticae, 257. 
Heterosporous condition, 114. 
Heterospory, 703, 716; in Se/aginella, 317 ; 
in Jsoetes, 318; in Lepédostrobus, 3243; in 
Calamostachys, 381. 
Hippuris, 178. 
Hofmeister’s Vergleichende Untersuchungen, 
14, 33- 
Homogeny, 76. 
Homologous alternation, 76, 79. 
Homologous theory of alteration, 47. 
Homosporous condition, 113; ferns in Palaeo- 
zoic period, 497. 
Horsetails, 366. 
Hydrodictyon, 64. 
Hymenophyllaceae, phyletic position of, 654 
(Fig. 354) ; external characters, 575 (Figs. 
322, 323); spore-producing members, 576 
(Figs. 324, 327); anatomy, 582 (Fig. 328); 
_ classification, 585. 
Hymenophyllites delicatulus, 582; Weisstd, 
582. 
Hymenophyllum, habit, 575 (Fig. 322) 
sorus, §79 (Fig. 324 42s); sporangia, 579 
(Fig. 325); spore-enumerations, 580 ; 
