CONTENTS. 



PAGE 



Introduction 1 



Current views as to the exemption of vegetable tissue from attacks of micro- 

 organisms 2 



Methods used in experimental work 3 



Do healthy plant tissues normally contain bacteria ? 4 



Results of artificial inoculation of bacteria into vegetable tissues : 



1. With saprophytic species 5 



2. With species parasitic for animals 6 



3. With species parasitic for plants . 7 



Conclusions derived and arguments to show that distribution of germs in tissue 



depends upon actual growth 8 



Can bacteria penetrate the intact healthy membranes of the plant ? 11 



The action of bacteria within the tissues, their mode of transport, etc 13 



Resistance and immunity of plants toward bacteria 15 



Distinction between normal resistance and immunity in the plant organism . . 17 



Examples illustrating the phenomena of resistance and immunity 20 



Causes producing this condition 23 



Physical 24 



Chemical 26 



Do plant juices possess germicidal properties ? 27 



Conclusions 32 



Bibliography 34 



Appendix giving a tabular resume of all the bacterial plant diseases known to 



date . . 35 



