rKKSlDKxNtTJAL ADDRESS SF.CTION C. 87 



but little has yet been done in this line in connection with 

 bacterial diseases. Many cases of varietal or individual immunity 

 have been observed, but it frequently happens that varieties which 

 are immune to disease have other less desirable qualities. 



The lines along which the problem of disease resistance 

 should be dealt with in the future, are ably summed up by Appel 

 (2) in the concludinir paragraph of his paper on disease resist- 

 ance in plants. He says that " the present methods should by 

 no means be abandoned, for j)ractical experience and happy 

 accidents may help a great deal, but in addition to carrying out 

 these methods, an effort must be made to find the causes cf 

 immunity, and after solving this question, to determine withottt 

 infection the disease-resistant qualities in different varieties and 

 individuals, in order to be able to establish the desired resistance 

 and at the same time to eliminate undesirable qualities. It is only 

 by working along this line that the breeding of disease-resistant 

 varieties on a scientific basis can be accomplished." 



LITERATURE CITED. 



Abe. Ktimanosuke — 



1. Citrus Canker in Japan. Phytopathology. VIII. 



(1918.). P. 44.3- 



Appel, O. — 



2. Disease resistance in plants. Science n.ser. XLI. 



773-782. 28-5-15. 



Arthur, J. C. — 



3. Diseases of the Pear. — A''. York Agric. Expt. Sta. Kept. 



3. 357-367 (1884). 



4. Histology and Biology of the Pear Blight. — Proc. Phil. 

 Acad. Nat. Sc. (1886), 322-341. 



Barker, R. T., and Grove, O. — 



5a. A bacterial disease of fruit blossom. — Ann. App. Biol., 

 Vol. I, 1914, p. 85. 



Barss, H. F.— 



5b, Bacterial gummosis of stone fruits. — Mo. Bull. Com. 

 Hort. Cal. 7 (1918) No. 3. 121-136. 



Boncquet, p. a. — 



6. Bacillus monilans. n.sp.. a bacterial organism found 



associated with curly top of sugar beet. — Phytopath. 7 

 ( T917). No. 4, 269-289. 



BRvOili, J. J., and Schikorro — 



7. Ber. d. dent. hot. Cescll. Vol. XXXI. Part 7, 1913. 



