ILLUSTRATIONS, 



PLATES. 



Plate I. Fig. 1.— Daisy on daisy; three needle pricks on each branch; time, 

 2 months 10 days; natural size. Fig. 2.— Daisy on daisy; time, 



7 months; three-fourths natural size 201 



II. Fig. 1.— Peach on rose. Fig. 2.— Apple on apple; galls at X, X. 

 Fig. 3.— Hop on tomato. Fig. 4.— Chestnut on sugar beet. Fig. 

 5.— A and B, daisy on potato. Fig. 6.— Rose on sugar beet 201 



III. Top.— At right, B and D, daisy on oleander; at left, natural gall on 



oleander from California. Bottom.— Hard gall of apple on daisy. 



IV. Fig. 1.— Nematode gall on sugar beet, from Chino, Cal., 1909. Fig. 



2. — Daisy on red radish 201 



V. Fig. 1.— Daisy on grape. Fig. 2.— Daisy on gray poplar 201 



VI. Fig. 1.— Daisy on peach, at end of 10 months; about two-thirds 



natural size. Fig. 2.— Peach on sugar beet, at end of 37 days 201 



VII. Fig. 1.— Daisy on carnation. Fig. 2.— Rose on daisy. Fig. 3.— 



Alfalfa on sugar beet 201 



VIII Daisy on sugar beet, at end of 4 months; both plants from same 



201 

 series ; ■ •'"^ 



IX. Fig. 1. — Daisy on hop. Fig. 2.— Daisy on cut surface of raw turnip 



in covered Petri dish, in laboratory. Fig. 3.— Grape on almond . . 201 

 X. Fig. 1.— Grape on grape. Fig. 2.— Grape on daisy. Fig. 3.— Grape 



on daisy; from same series as Fig. 2, but 3 months later 201 



XI. Fig. 1.— Peach on peach. Fig. 2— Daisy on peach. Fig. 3.— 



Peach on peach (another series) 201 



XII. Fig. 1.— Hop on sugar beet, at end of 31 days. Fig. 2.— Peach on 



apple (hard gall), at end of 2 years 201 



XIII. Peach on daisy. Fig. 1.— At end of 5 months 12 days. Fig. 2.— 



At end of 4 months (second time through peach) 201 



XIV. Peach on geranium (Pelargonium), at end of 3 months; slightly 



under natural size 201 



XV. Fig. 1.— Apple on daisy, at end of 10 months. Fig. 2.— Hop on 



almond (one gall on crown; one on stem above crown) 201 



XVI. Fig. 1.— Chestnut on daisy; less than natural size. Fig. 2.— a, 

 Alfalfa on alfalfa; b, ordinary nitrogen-fixing nodules of alfalfa, 



introduced for comparison 201 



XVII. Hairy-root of apple on sugar beet. Figs. 1 and 2.— From one series 



of inoculations. Fig. 3.— From another series 201 



XVIII. Apple hairy-root on young apple trees. Fig. 1.— Hard gall at X. 

 Fig. 2.— Typical fleshy roots at right of X; both photographed 



after 7 months in alcohol 201 



XIX. Hairy -root of apple inoculated on sugar beet 201 



213 ^^ 



