LIST OF ILLUSTRATIONS XXIX 



Page 



409. Small intumescences on potato stems abundantly supplied with water 



but top destroyed by Bacillus pkytophthorus 542 



410. Same as figure 409, but further enlarged and from the other side of the 



stem 544 



411. Intumescences (hyperplasias) on potato shoots which are dwarfed for 



lack of water — tissues full of sugar, starch, acids and oxydizing 

 enzymes, base of shoots tumefied 546 



412. Vertical section through intumescences under stomata on a potato shoot 



(see figure 411). Tissue gorged with starch 547 



413. Surface view of hyperplasias on potato shoots from figure 411. Stoma 



central and wide open over each one 548 



414. A. B. Structure of a very young nematode tumor with the young worms 



in place. Shows both hypertrophy (giant cells) and hyperplasia. . . . 550 



415. Structure of a polythalamous gall on Rosa rubiginosa (the sweetbriar) 



leaves of an unusual type, i.e., somewhat resembling the calyx lobes. 552 



416. Magnified section of a part of fig. 415B with two attached leaves 5.54 



417. Monothalamous cynipid gall from an oak tree {Quercus prinus ?): 



leaves of an unusual type, i.e., resembling those of the willow-leaved 

 oak 556 



418. A. B. Enlarged views of the oak gall with some of the linear leaves 



removed 557 



419. Stained section of the center of fig. 4185 magnified 25 times 559 



420. Side wall of fig. 419 further enlarged to show its structure 560 



421. Outer one-half of top wall of fig. 419 561 



422. Tangential section of the oak gall passing through the middle part of 



the wall — small cells of the hyperplasia in the middle, larger ones at 

 either side, i.e., nearer the surface and farther from the larval ex- 

 cretions 562 



423. Tangential section of the wall of the oak gall showing, in the middle, 



the deep staining hypertrophied inner nutritive layer 564 



424. A. B. C. Cells of the hypertrophied inner layer, some containing more 



than one nucleus. Highly magnified 565 



425. Ordinary appearance of Begonia phijllomaniaca 576 



426. Non-proliferous and proliferous shoots of Begonia phijllomaniaca 577 



427. Enlarged central part of a dwarfed proliferous leaf showing that the 



proliferations are not restricted to the main veins 578 



428. A, B. Structure of leaf buds of Begonia phyllomaniaca; C. Plant grown 



from an adventive shoot on a leaf blade; D. Enlarged view of stem- 

 lenticels and glands 580 



429. A, B. Proliferation on shoot and leaf stalk of Plant No. 1, first series, 



front and back view; C. Proliferation and beginning cork formation on 



a branch of the same 582 



430. 431. Dwarfed proliferous leaf of No. 1, first series, and next four leaves 



above it 584, 585 



432. Plant No. 6, first series, showing proliferous leaves and internodes with 



non-proliferous ones above and below 586 



433. Plant No. 6, first series, showing proliferous upper face of leaf blade Z 



and nearly smooth face of Z^ next below it 588 



434. (1) Lower (free) and (2) middle (leafy) internodes of No. 6, first series; 



