682 



Olive tubercle, nomenclature of organ- \ 

 ism causing, 394 

 no tvmior strands in, 389 

 structure of, 389 

 type of disease, 389 

 wild olives subject to, 389 

 wound infection, 389 

 Opium poppy, bacterial disease of, 54 

 Orchard grass, new type of infection 

 found in. 48 

 Rathay's disease of, 473 

 Osier (Sir Wm.), wisdom of, 661 

 Oven, for sterilizing glassware, 78 

 Overgrowths, as a result of bacterial 

 infection, 50 

 how otherwise produced, 477 

 Oxygen and the bacterial cell, 515 

 and the tumor-cell, 511, 531, 541 



Paintings, for illustration, 129 ! 



Panama disease of banana, 52 } 



Panchromatic plates, use of, in photo- 



micrographic work, 95 

 Paraffin oven, 83 



Parasites, sensitive to environment, 12 

 action on tissues, 46 

 dry air sensitive, 135, 195, 231, 



257, 306, 322, 372, 421 

 dry air resistant,' 147, 161, 207, 



285, 348 

 effect of freezing on, 285, 306, 



322, 372 

 effect of moisture, 13 

 effect of shade, 13 

 effect of sunlight, 156, 231, 285, 



306, 322, 349, 369, 404, 421 

 effect of winds, 13 

 extracellular versus intracellu- 

 lar, 46 

 kiUing temperatures, 135, 139, 

 155, 214, 231, 272, 285, 308, 

 327,348,371,399,426 

 soon followed by saprophytes, 34 

 summer temperatures, stimula- 

 ting effect of, 13 

 summer temperatures repressive 

 effect of, 310 

 Parasitism versus symbiosis, 41 I 



Pasteur, wisdom of, 642, 656 I 



Pavetta nodules, figures illustrating, 42 , 



43, 44, 45 

 Pea, stem bUght of, 474 

 Peach, black spot of, 473. (See Bac- 

 terium pruni.) 

 Pear blight, 359. (See also fire-bUght 

 and Bacillus amylovorus.) 

 discovery of bacterial origin of, 1 

 economic importance of, 54 

 enormous losses due to, in United 



States, 55 

 how spread, 68 

 in stone fruits also, 69, 359 

 methods of control, 68, 385 * 

 occurs now in Japan, 365 

 Pelargonium, leaf-spot, 474 

 Peptone water, use as culture media, 



106 

 Peroxidase in tumors, 563 

 Pethybridge and Murphy, potato rot of, 



64 

 Phenolphthalein, how used in titrations, 



106, 132 

 Philippines, bacterial diseases found in, 



54 

 Photographs, preparation of, 120 

 Photography, 

 cameras, 90 

 lenses, 91 

 room for, 89, 96 

 value of, 121 

 washing devices, 95 

 Photomicrographs, camera for use in 

 making of, 94 

 developer for, 125 

 fixing bath, 125 



light filters, use of, in making, 94 

 preparation of, 123 

 time of exposure for, 124 

 Phyllomania in Begonia, 574-630 

 abnormalities observed in, 615 

 causes distortions, 612 

 comparison with effect of anaesthe- 

 tics on dormant buds, 622 

 comparison with effect of cold, 622 

 comparison with effect of heat, 623 

 due to shock, 575 

 epidermal nature of, 583 

 from glands and trichomes, 583 

 from wounds, 590 



