go2 



Plants. Relation to environment 10-13 



— Relation to nutritive sub- 



stances 274-319 



— Rupture of fleshy parts 3^ '-34 



— Statistics of disease 71 



— Stunting 175-/7 



Plants, Herbacious. Effect of changes 



in habitat 72-75 



— Tropical 190 



— Woodv. Adjustment of root 



body 78-81 



Development of axis 76-78 



Plants injured by drought. Effect of 

 moist air 425-26 



Plasm, Eml)ryonic 31 



— Hereditary 31 



PlasiiioHiofyliora Brassicac 364 



Plasjiiopara viticola 280 



Plaster, Land 195, 237-40, 250, 402 



Plaster fertilization 237-40 



Plastidcn theory 62 



Plastidules 31 



Platanus orieiitalis. Effect of lack of 



calcium 304 



Plectridia. Pectin fermenting organ- 

 isms 272 



Pleophylly 376 



Pleospora guuiinipara. Oud 708 



Plowing, as inducing soil ripening" 277, 



Plowing, Deep, in heavy soil 234 



Plums. Tan disease 218 



— Varieties for dry soils I75 



Plums, Rusty 166 



Poa alpiiia 76 



Podocarpus. Nanism 144 



Podosphaera lencotricha. Salm 640 



Poefih of tobacco 685 



Poisoning due to lack of calcium 304 



— of soil 266 



Pole red of hops 283 



Polycladia 146 



Polygonum amphibiuvi 176 



— vivipanun 76 



Poly poms snlfurcus 568 



Polysarchia 53 



Pomes. Dropsy 338-39 



Pomological magic ring 789 



Poplar. Bleeding disease 887 



— Jaundice 887 



Poplar, Pyramidal. Death 558 



Position, Cultural, of plants 55 



— Horizontal. Effect of changes. .. 120-28 



Pot cultures. Soil 140 



Potassium. Excess 403-5 



— Lack. Effect on production. . .298-301 

 in Sfci-if/matocystis nigra 300 



Potassium chlorid treatment of moor 



soil 257 



Potassium fertilization 129, 156 



Potassium hyperchlorate 767 



Potatoes. Aerial tubers 165 



— Bacterial ring disease 398 



— Black dry rot 391 



— Brown specks on foliage 397 



— Cultural varieties 209 



— Diaphysis 163-64 



Potatoes. Effect of hail 466 



— Enlarging of the parent tuber 398 



— Iron spottedness 391, 882 



— Leaf curl 395-W, 882 



— Lcnticels 369 



— Lightning eft'ect 495 



— Mules 161-63 



— Multi-colored condition 391 



— Over-fertilization 390-91 



— Perforation of the foliage 430 



— Premature ripening 161 



— Prolepsis 163 



— Running out 208-209 



— Rupturing of the stem 321 



— Scurvy, Deep 430 



— Secondary tuber formation 163 



— Thread formation 161-63 



— Tuber cuttings 828 



formation without foliage 164 



— Turning sweet 514-16 



— Water ends 163 



Potatoes, Seed. Method of cutting 828 



Pots, Flower. Washing 205 



Potted plants. Encrustation of the soil. 205 



Souring 203-206 



Use of saucers 208 



Pox of tobacco 689-90 



Prateolus 53 



Predisposition 25-26, 27-34, 52, 62, 



83, 128, 223, 225, 301, 666-70. 

 Predisposition. Abnormal 26 



— Hereditary 83 



— Normal 26 



Predisposition and immunity 27-31 



— to blight .' 52 



— to disease, Inheritance 31-34 



due to lack of light 666-70 



due to lack of nutriment. .. .301 



in beets 223, 225 



in edible roots 223, 225 



-^ to the mosaic disease 687 



— to the smoke diseases 722 



— See also Disposition. 



Pressure of the buds 378 



Production. Changes due to lack of 



nitrogen 287-98 



Prolepsis of the potato 163 



Proliferation 374 



— Axillary 375 



Proliferation of the inflorescences 374 



Prophylaxis 7 



Prosenchyma, Horn 707 



Protandry 293 



Proteins. Decomposition due to lack 



of light 669 



Prothallia, Ameristic 288 



Protogyny 293 



Prunulus 53 



Prunus 107 



— Nanism 144 



Pniiius avium. Discoloration 280 



— Cerasns. Discoloration 281 



— domcstica. Discoloration 280 



— Padus. Goitre gnarl 385 



— pcrsica. Discoloration 280 



