Index to Vols. XXI-XXX. 
Podostemaceae and Tristichaceae, origin of, 
2 9 , 299. 
Poisons, action of, on Chlamydomonas and 
other vegetable cells, 23 , 181. 
Pollen-grains of Fuchsia, supernumerary, 21 , 
305. 
Pollen mother-cells, chromatin extrusion in 
Lilium candidum (*), 29 , 285 ; hetero- 
typic chromosomes (*), 21, 309 ; walls (*), 
23 , 494. 
— of Calycanthus floridus (*), 23 , 30 ; of 
Richardia africana (*), 23 , 34 ; of Thalic- 
trum purpurascens (*), 23 , 21. 
Pollen-presentation mechanism in the Com- 
positae (*), 29 , 457. . 
Pollination, influence of, on respiratory ac- 
tivity of gynoecium, 21, 487. 
— insect visitors of flowers of Clova Moun- 
tains, 22, 603. 
— mechanisms of Lagenostomales (*), 25 , 
• 38 . 
Polyalthia suberosa, vascular anatomy (*), 
22, 670. 
Polycarpon tetraphyllum, seedling-structure, 
26 , 1 81. # 
Polygonum, spp., extra-floral nectaries of (*), 
23 , 229. 
— viviparum, insect visitors, 22, 608. 
Polylophospermum, note on (*), 21 , 303. 
Polymorphism of organism causing root- 
tubercles of Alnus and Elaeagnus (*), 26 , 
119. 
Polyphagus Euglenae, chromidial fusion, 27 , 
184; chromidia (*), 27 , 182; cysts, 27 , 
179; effect on Euglena, 27 , 175 ; germi- 
nation of zygote (*), 27 , 185; nuclear 
division (*), 27 , 189; occurrence and 
habit, 27 , 174 ; relationships, 27 , 192 ; 
reproduction (*), 27 , 178 ; thallus-struc- 
ture (*), 27 , 176 ; zoospores (*), 27 , 177 ; 
zygote formation (*), 27 , 179. 
Polypodium aureum, cytology (*), 24 , 193. 
— Schneideri, cytology (*), 24 , 200. 
— sinuosum, symbiosis with ants, 24 , 465. 
— vulgare, cytology (*), 24 , 195. 
var. elegantissimum, cytology (*), 24 , 
198. 
Polystigma rubrum, ascogonia (*), 26 , 763; 
mycelium (*), 26 , 762 ; spermogonia (*), 
26 , 763. 
Poly trichum, abnormal cell fusion in arche- 
gonium and spermatogenesis (*), 27 , 
115. 
Populus, structure of North American (*), 
26 , 165. 
— balsamifera, anatomy of leaf-fall (*), 25,69. 
Porella, spermatogenesis (*), 25 , 299. 
Porometer, a recording (*), 30 , 47. 
— in stomatal investigation, use of (*), 30 , 
57 - 
Poroxylon Sutcliffi, description, 24 , 237. 
Portulaca oleracea, seedling-structure (*), 
26 , 177. 
27 
Portulacaceae, seedling-structure (*), 26 , 
175 - 
Portulacaria and Ceraria, comparative ana- 
tomy «(*), 26 , 1111. 
Potassium, role of (*), 21 , 502, 517. 
Potato leaves, bacterial disease, 26 , 133 ; 
histology of affected plants (*), 26 , 135 ; 
infection (*), 26 , 143 ; symptoms and 
mode of occurrence, 26 , 133 ; the para- 
site (*), 26 , 137. 
— tubers, cause of ‘blindness ’, 26 , 129. 
Potentilla, spp., insect visitors, 22 , 624; 
seedling-anatomy, 28 , 723. 
Poulton, E. M. : The Structure and Life- 
history of Verrucaria margacea, Wahl., 
an Aquatic Lichen (*), 28 , 241. 
Prain, D. : A Review of the Genera Ery- 
thrococca and Micrococca, 25 , 575. 
— The Mercurialineae and Adenoclineae ot 
South Africa, 27 , 370. 
Prankherd, T. L. : Notes on the Occur- 
rence of Multinucleate Cells (*), 29 , 599. 
— On the Structure and Biology of the 
Genus Hottonia (*), 25 , 253. 
Preissia commutata, mitosis in vegetative 
cells (*), 27 , 66 i ; sporogenesis (*), 27,670. 
Prepinus, description, 24 , 398. 
— japonicus, n. sp., description, 24 , 398; 
leaf-structure (*), 24 , 396. 
Price, S. R. : Some Studies on the Structure 
of the Plant Cell by the Method of Dark- 
ground Illumination (*), 28 , 60 r. 
Priestley, J. H. : see Knight, R. C. 
— and Irving, A. A. : The Structure of the 
Chloroplast considered in Relation to its 
Function (*), 21 , 407. 
Primula, chromosome numbers, 26 , 359 ; 
cytology (*), 26 , 357 ; premeiotic divi- 
sions (*), 26 , 361. 
— floribunda, cytology (*), 26 , 363. 
isabellinax P. kewensis, cytology, 26 , 
377 - 
— kewensis, seedling-form, cytology (*), 26 , 
372 . 
type, cytology (*), 26 , 370. 
farinosa, cytology (*), 26 , 376. 
— verticillata, cytology (*), 26 , 369. 
x P. floribunda, cytology, 26 , 376. 
Prince Edward Island, fossil plants from (*), 
27 , 244. 
Pro-embryo and bulbils of Lamprothamnus 
alopeciiroides (*), 21, 61. 
Proliferous form of scape of Plantago lan- 
ceolata (*), 30 , 353. 
Propagation in Drosera, vegetative (*), 29 , 
308. 
Prophase of first division, conjugation of 
chromosomes in (*), 23 , 46. 
— of heterotypic mitosis in the embryo-sac 
mother-cell of Lilium (*), 23 , 343. 
Protea Lepidocarpon, embryo-sac, 23 , 161. 
Proteases of oily seeds, separation, 22 , no. 
— of plants, 22 , 103 ; 23 , 1 ; 24 , 213. 
