Index to Vo Is, XI-XX. 
o. 
Obolaria virginica, anatomy and morphology 
(*), xi. 369. 
Oceanic islands, powder-seed plants in, xix. 
362. 
Odontites rubra, excretion of water by 
leaves, xi. 392. 
Oedocephalum glomerulosum, description 
(*), xvi. 80. 
• — ochraceum, n. sp., description (*), xvi. 
80. 
Oedogonium, development and structure of 
young plants (*), xvi. 467 ; xviii. 648 ; ger- 
mination of zoospores (*), xvi. 412 ; zoo- 
spores, abnormal formation and develop- 
ment (*), xvi. 481. 
Oidiopsis sicula — O. taurica, xx. 198. 
Oidiopsis taurica, an endophytic member of 
the Erysiphaceae (*), xx. 187 ; descrip- 
tion (*), xx. 195 ; distribution, host-plants, 
and synonymy, xx. 194, 198. 
• var. lanuginosa, description, xx. 199 ; 
distribution and host-plants, xx. 199 ; 
synonymy, xx. 198. 
Oidium gignsporum — O. taurica, xx. 198. 
— Haplophylli — O. taurica, xx. 198. 
Oliver, F. W. — The Ovules of the Older 
Gymnosperms (Plate XXIV and one 
text-figure) (t), xvii. 451. 
— and Scott, D. H. — On Lagenostoma 
Lomaxi, the seed of Lyginodendron (t), 
xvii. 625. 
On the Structure of the Palaeozoic 
Seed Lagenostoma Lomaxi, with a State- 
ment of the Evidence upon which it is 
referred to Lyginodendron, xviii. 321. 
Onoclea, fertilization (*), xii. 261. 
Oogenesis in Nemalion multifidum (*), xviii. 
613. 
Oospore of Pinus Strobus, division of (*), 
XV. 449- 
Oospores of Cutleria, germination (*), xii. 
85. 
Ophioglosseae, root-structure (*), xiii. 377 ; 
secondary thickening (*), xiii. 386 ; spo- 
rangia, imperfect, xv. 256. 
Ophioglossum, germination of spores, xx. 
321 ; sporangia, imperfect, xv. 256. 
— pendulum, antheridium development (*), 
xvi. 29; archegonia development (*), xvi. 
30 ; embryo (*), xvi. 31 ; mycorhiza of 
prothallus .(*), xvi. 27, 28 ; prothallus (*), 
xvi. 25 ; root-structure (*), xiii. 380. 
— simplex, morphology and structure (*), 
xviii. 205. 
— vulgatum, root-structure (*), xiii. 378 ; 
secondary thickening (*), xiii. 386. 
Optima and limiting factors, xix. 281. 
Opuntia, morphology of embryo and seed- 
ling (*), xii. 439. 
Orange, pleiotaxy of gynaecium (*), xvi. 
154- 
27 
Ornithogalum exscapum, seedling-structure, 
xvii. 21. 
— sulphureum, seedling-structure, xvii. 20. 
Osmotic optimum and measurements, xii. 
568. 
Ovule, morphology and structure (*), xviii. 57; 
of the older Gymnosperms (* +), xvii. 451. 
Oxidase and enzyme, xvii. 257. 
Oxidases in latex, xiv. 199. 
P. 
Palaeozoic Lycopods, occurrence of seed- 
like fructification in (t), xiv. 713. 
— plants, Megaloxylon, a new genus of (f), 
xiii. 612. 
— seed types, ordinary (* +), xvii. 453. 
Palmae, seedling-structure, xvii. 47. 
Palmellaceae, evolution and polymorphism, 
xi. 101. 
Papain, xix. 149 ; proteolytic action, xvi. 5. 
Papaver cambricum, description, xx. 343. 
— — - perenne Jiore sulpkureo, description, xx. 
343- 
— crassifolium , description (*), xx. 345. 
— heterophyllum, description (*), xx. 344. 
•var. crassifolium, description (*), xx. 
345- 
— paniculatum , description, xx. 358. 
— - simplicifolium, description, xx. 354. 
Paper, structure of an ancient, xii. hi. 
Papillae in epidermoidal layer of calamitean 
root (* t), xviii. 645. 
Parasite and host, relations between in 
Bromus and Puccinia dispersa, xvi. 233. 
Parasitism, Eriksson’s hypothesis, xix. 21. 
— of Aecidium graveolens (*), xii. 155 ; of 
Fungi, recent researches in, xix. 1 ; origin 
of, xviii. 319 ; of Harveyella mirabilis (*), 
xiii. 26 ; of Uredineae, xix. 14, 55; of 
Urophlyctis, xi. 87. 
Parental characters, distribution of to the 
germ cells, xix. 246. 
Parichnos, function, xx. 271 ; in Isoetes 
Hystrix, xviii. 654 (*), xx. 268 ; in Lepido- 
dendron (*+), xx. 271 ; in Lycopodium (*), 
xx. 269 ; in recent plants If +), xviii. 654 ; 
xx. 267. 
Parkin, J. — Observations on Latex and its 
F unctions (Plate XII), xiv. 193. 
— On a brilliant Pigment appearing after 
Injury in Species of Jacobinia (N. O. 
Acanthaceae), xix. 167. 
— On some points in the Histology of 
Monocotyledons (Plate XIII), xii. 1 47. 
— On the Reserve Carbohydrates of the 
Bulb of the Hyacinth (Hyacinthus orien- 
tals), xiv. 155. 
— Some Observations bearing on the Func- 
tion of Latex, xiii. 620. 
— The Extra-floral Nectaries of Hevea 
brasiliensis (the Para Rubber tree), an 
Example of Bud-scales serving as Nectaries 
(Plate XVI), xviii. 217. 
