CONTENTS. 



Page 



Introductory 7 



Published accounts relating to crown-gall 8 



Opinions regarding the communicability of crown-gall 10 



Geographical distribution of crown-gall in the United States 12 



Some statements of other observers regarding crown-gall 13 



Field experiments in the Salt River Valley M 



History of some of the trees treated with Bordeaux mixture 16 



Effect of Bordeaux mixture on the disease 18 



Observations on seedlings in the Salt River Valley 18 



Experiments in inoculating soil with minced galls in 1S97-189S 21 



Experiments in inoculating healthy seedlings by making incisions 



through the bark and inserting bits of the gall tissue 23 



An experiment with water cultures 2 5 



Experiments in inoculating soil with minced galls in 1S9S-1899 26 



Experiments in growing seedlings in pots filled with crushed quartz 2S 

 Second series of experiments in inoculating healthy seedlings by 

 making incisions through the bark and inserting bits of the gall 



tissue • • • • 2 9 



The effect of excision of the galls and of the application of fungicides . 30 



Some miscellaneous experiments relating to crown-gall 30 



Plants subject to crown-gall 3 2 



The structure and development of the gall 33 



The cause of crown-gall 39 



The Plasmodium and its transitory resting stages 40 



The effect of .the plasmodium upon the cytoplasm of the host cell. . . 46 



The fructification ... • • 5 2 



Generic and specific diagnosis 55 



How the disease spreads 5° 



Losses caused by crown-gall 5^ 



Remedies for crown-gall • " : 



Spore inoculations °3 



Comparisons with some recent investigations on Plasniodiophora . . . 63 



(3) 



