Index to Vols. XXI-XXX. 
23 
Narcissus, morphology of corona (*), 28 , 541. 
Narthecium Ossifragum, insect visitors, 22 , 
635. 
Natural selection and geographical distribu- 
tion (*), 30 , 1 ; and isolation, 25 , 743. 
Nectaries of Polygonum, extra floral (*), 
23 , 229. 
Nemesia, spp.> seedling-anatomy, 26 , 738. 
Nereocystis Luetkeana, histology, 22 , 320. 
Neurospermum, n.gen., description (*), 28 , 
93 , 103. 
— Kidstoni, n. sp ., description (*), 28 , 103. 
New Brunswick, fossil plants from (*), 27 , 
248. 
New Zealand, distribution of species in (*), 
30 , 437 ; early type of Abietineae from 
Cretaceous of (*), 30 , m; Jurassic Os- 
mundaceae from (*), 28 , 471. 
Nicandra physaloides, seedling-anatomy (*), 
26 , 733. 
Nicotiana alata, seedling-anatomy, 26 , 736. 
Nierembergia gracilis, seedling-anatomy, 26 , 
737 . 
Nigella, spp., seedling-anatomy, 28 , 707. 
Nilssonia orientalis, structure (*), 24 , 389. 
Nitrogen fixation by Azobacter, conditions, 
26 , 871. 
Nopalea, seedling-structure (*), 24 , 134, 
Notothylas, sporogonium (*), 21 , 201. 
— javanicus (*), 22, 96; embryo (*), 22, 
97 ; reproductive organs (*), 22, 97. 
Nuclear division in Compositae (*), 26 , 705 ; 
Desmids (*), 30 , 379 ; Galtonia candicans 
(*), 24 , 726 ; mechanism of (*), 24 , 653 ; 
Mnium hornum (*), 23 , 141 ; Preissia 
commutata (*), 27 , 661 ; Rusts, vegetative 
(*), 22 , 331 ; Tetraspora lubrica (*), 27 , 
681. 
— migration in Phragmidiufn violaceum (*), 
29 , 293. 
Nuclei in Ascomycetes, conjugate (*), 30 , 4 i 5 . 
Nucleolus, relation of, to chromatin bodies in 
Galtonia candicans (*), 23 , 491. 
— role of (*), 29 , 288. 
Nucleus, double nature of somatic, 23 , 43 ; 
genesis of male in Lilium (*), 28 , 265 ; 
organization of, in pollen mother-cells (*), 
23 , 19 ; studied under dark-ground illu- 
mination (*), 28 , 615 ; unisexual plants, 
23 , 341. 
Nutrient solution in water-culture, effect of 
concentration of, 29 , 89 ; (*), 30 , 77. 
— solutions, 21, 511. 
Nutritive elements to the plant-cell (*), 21, 
501. 
Nyctaginaceae, seedling-structure (*), 26 , 
189. 
Nyssa sylvatica, anatomy of leaf-fall, 25 , 95. 
O. 
Obione portulacoides, seedling-structure (*) 
26 , 184. 
Odontosoria, phylogeny (*), 27 , 459. 
Oedogoniaceae in the Tropics, 21 , 265. 
Oenothera, cytology (*), 23 , 551 ; 24 , 631; 
25 , 941 ; 26 , 993. 
anaphase (*), 26 , 1000; chromosome 
number (*), 26 , 993 ; metaphase (*), 26 , 
999 ; prophase (*), 26 , 995 ; reducing di- 
visions (*), 25 , 941 ; 26 , 1003 ; somatic 
mitoses (*), 26 , 993 ; telophase (*), 26 , 
1000. 
— biennis, reducing divisions in ovule (*), 
24 , 640 ; ' in pollen mother-cell (*), 24 , 
633; vegetative mitosis in ovule (*), 24 , 
643' 
— gigas, archesporium (*), 25 , 91 r ; chromo- 
some formation (*), 25 , 955, 959 ; mitosis 
(*), 25 , 921, 923, 930, 956, 957; nuclear 
extensions (*), 25 , 915 ; pollen formation 
(*), 25 , 909 ; pollen tetrads and pollen- 
grains (*), 25 , 925 ; presynapsis (*), 25 , 
954 ; size of cells and nuclei (*), 25 , 958 ; 
sterility (*), 25 , 927 ; synapsis (*), 25 , 
9i T , 9 1 9 ) 954- 
— grandiflora : chromosomes, formation of 
bivalent (*), 23 , 557 ; mitosis (*), 23 , 522, 
560,563; synapsis (*), 23 , 555; vegetative 
mitosis in anther (*), 552. 
— Lamarckiana, chromosome formation (*), 
25 , 946; mitosis (*), 25 , 948, 950; pre- 
synapsis (*), 25 , 944; sterility of pollen 
(*), 25 , 952 ; synapsis (*), 25 , 945. 
Oil of Helianthus annuus, chemical nature, 
26 , 894 ; reserve in germination, 26 , 
889. 
Oil-containing seeds, proteases of, 22 , 104. 
Olive, E. W. : Sexual Cell Fusions and 
Vegetative Nuclear Divisions in the Rusts 
(*), 22, 331. 
Oliver, F. W. : Note on the Palaeozoic 
Seeds, Trigonocarpus and Polylopho- 
spermum (*), 21, 303. 
— On Physostoma elegans, Williamson, an 
Archaic Type of Seed from the Palaeozoic 
Rocks (*), 23 , 73. 
— and Salisbury, E. J. : On the Structure 
and Affinities of the Palaeozoic Seeds of 
the Conostoma Group (*), 25 , 1. 
Olpidiopsis (*), 26 , 209 ; description of 
species, 26 , 230 ; infection of host (*), 26 , 
215; nuclear division, 26 , 229; sexual 
organs (*), 26 , 219, 227; sporangium 
development (*), 26 , 217, 255 ; zoospores 
(*)> 26 , 213. 
— luxurians, n. sp., description, 26 , 231. 
— Saprolegniae, description, 26 , 232. 
— vexans, n. sp description, 26 , 231. 
Onoclea, phyletic consideration, 26 , 300. 
Onopordon tauricum, seedling-structure, 
28 , 320. 
Ophioglossaceae, morphology and anatomy 
(*), 24 , 1; 27 , 203; 28 , 19; 29 ? 1; 
primary xylem and origin of medullation 
(*), 25 , 537 . 
