Index to Vo Is. XI -XX. 
3i 
Promycelium of Gymnosporangium clava- 
riaeforme (*), xviii. 329; of Phragmidium 
violaceum (*), xviii. 327. 
Proserpinaca palustris, heterophylly (*), xviii. 
579 - 
Protease, nature of fibrin-digesting, xix. 172. 
Proteases and antiseptics, xvii. 602. 
— of Agaricus campestris, xix. 179 ; *\nanas 
sativus, xix. 177 ; Carica Papaya, xix. 176 ; 
Hordeum sativum, xix. 179 ; Hyacinthus 
orientalis, xix. 182; Nepenthes, xix. 183; 
Polyporus squamosus, xx. 51 ; Saccharo- 
myces cerevisiae, xix. 178. 
— of plants, xviii. 289; xix. 149, 171 ; xx. 113. 
Protective adaptations (*), xx. 123; Ana- 
campseros papyracea (*), xx. 126; Mesem- 
bryanthemum Bolusii (*), xx. 125; Me- 
sembryanthemum truncatum (*), xx. 123. 
— movements of leaves against excessive 
insolation, xi. 447, 585. 
— red dye, xi. 460, 585. 
Proteids of latex, xiv. 195. 
Proteid vacuoles of archegonium of Pinus 
Strobus (*), xv. 459. 
Proteolysis, tryptophane in, xvi. 1. 
Proteolytic enzymes in bulbs, xvii. 250 ; in 
fruits, xvii. 242 ; in laticiferous plants, xvii. 
246; in leaves, xvii. 249; in Nepenthes, 
xi. 563 ; xii. 545 ; xv. 563 ; in plants, xvii. 
2 37, 597; in roots, xvii. 251; in seeds, 
xvii. 241; in stems, xvii. 247; in tubers, 
xvii. 251. 
Prothallus of Helminthostachys zeylanica (*), 
xvi. 23 ; Lycopodium clavatum (*), xiii. 
279 ; Ophioglossum pendulum (*), xvi. 
23 ; Psilotum triquetrum (*), xviii. 571 ; 
Schizaea bifida, xvi. 165. 
Protococcaceae, evolution and polymor- 
phism, xi. 107. 
Protoplasm, action of hydrogen on streaming 
of, xix. 523. 
— action of carbon dioxide on streaming of, 
xix. 526. 
— in coenocytic hyphae, movements of (*), 
xi. 491. 
Protoplasmic body in Florideae, form of, 
xii. 569. 
Protostele, definition, xvi. 523. 
Psaronius, comparison with Marattiaceae (t), 
xvi. 381. 
Pseudomonas hirtum, cell-contents (*), xx. 
254; cell-division (*), xx. 248 ; characters 
(*), xx. 255; ciliation (*), xx. 252; cultures 
(*), xx. 237; development of spores (*), 
xx. 250; germination of spores (*), xx. 
236; growth (*), xx. 241 ; motility, xx. 
252 ; spores (*), xx. 234. 
Pseudo-Pleurococcus, n.gen ., description (*), 
xiii. 189, 194. 
— botryoides, n. sp., description (*), xiii. 191, 
194. 
— vulgaris, n.sp ., description (*), xiii. 193, 194. 
Psilotaceae, imperfect sporangia, xv. 254. 
Psilotum triquetrum, leaf-structure (*), xviii. 
594; morphology (*), xviii. 505, 589; 
mycorhiza (*), xviii. 573, 597; prothallus 
(*), xviii. 571 ; secondary thickening (*), 
xviii. 508; sexual organs (*), xviii. 573 ; 
sporangia imperfect, xv. 254 ; stem-struc- 
ture (*), xviii. 507, 592, 594, 59 < 5 , 598. 
Pteridophyta and Gymnosperms, anatomy 
and development of stem, xv. 779. 
— Bower’s classification, xvii. 618. 
— imperfect sporangia, are they vestigial ? 
xv. 225. 
— - nature and origin of primitive stele, xv. 35. 
Pteridospermae, a new class of fossil plants 
(t), xviii. 322. 
Pteridospermous seed from the Coal Mea- 
sures, new species of Lagenostoma, a type 
of (* +), xix. 326. 
Pteris elata var. Karsteniana, structure (*), 
xvii. 702. 
— palmata, seedling-structure, xix. 397. 
Pterospora andromedea, morphology (*), 
xiii. 31 ; mycorhiza (*), xiii. 34; structure 
of vegetative organs, xiii. 34. 
Ptilota plumosa, cystocarp development (*), 
xi. 361. 
Puccinia Adoxae, sexuality of (*), xx. 43. 
— dispersa and Bromes, xv. 560 ; xvi. 233 ; 
xix. 19. * 
experiments on, xvi. 487 ; germination 
of uredospores, xvi. 261. 
— glumarum, histology, xix. 35. 
— Malvacearum, sexuality of (*), xx. 42. 
— Poarum, sexuality of (*), xx. 40. 
Pyronema confluens, sexual reproduction (*), 
xiv. 321. 
Pythium de Baryanum, fertilization (*), xv. 
659; oosphere, formation (*), xv. 659; 
oospore, maturation (*), xv. 661 ; sexual 
organs, development (*), xv. 656. 
— ultimum, n. sp., biology and cytology (*), 
xv. 269 ; conidia-formation, xv. 278 ; de- 
scription (*), xv. 300 ; dissemination of 
spores, xv. 285 ; fertilization (*), xv. 280; 
germination of conidia (*), xv. 276; ger- 
mination of oospores, xv. 282 ; growth 
and temperature, relation between, xv. 
286; growth of mycelium, xv. 277 ; matura- 
tion of oospores (*), xv. 281, 289; sapro- 
phytism,xv. 286 ; sexual organs, formation 
(*), xv. 278, 289 ; temperature and growth, 
relation between, xv. 286. 
Pyxisporeae, observations on (*), xii. 40. 
CL 
Quadripolar spindle in the spore-mother- 
cells of Pellia epiphylla, xv. 431. 
R. 
Ranunculaceae, seedling-structure (*), xvii. 
52. 
Ranunculus Ficaria, seedling-structure (*), 
xvii. 63. 
