34 H. L. Russell 



factors. The exemption of plants from bacterial diseases, however, 

 does not rest upon any single factor but upon the interaction of 

 various causes. 



Added to this mechanical source of immunity are the chemical 

 reaction of the juices, the unfavorable conditions of nutrition, the 

 action of the living protoplasm, etc., all of which exercise an unfa- 

 vorable or inhibitory effect on bacterial life. 



The whole question of immunity of plants from bacteria is much 

 more closely related to the same question as regards fungi than it is 

 to the subject of immunity as seen in the animal kingdom. Vege- 

 table cell juices, aside from their acid reaction, are entirely powerless 

 against bacteria, and do not possess any germicidal properties like the 

 blood-serum of animals. 



BIBLIOGRAPHY. 



A. On the normal presence of bacteria in healthy tissue: 



1. Bernheim : Munch, med. Wochen., 1888, s. 743. 



2. Buchner: Munch, med. Wochen., 1888, No. 52. 



3. de Vestea: Ann. de PInst. Pasteur, 1888, 670. 



4. Fazio: Revista inter. d'Igiene, 1890. (Abs. : Cent. f. Bakt. 



VII, 798.) 



5. Fernbach : Ann. Past., 1888, 567. 



6. Groucher et Deschamps: Arch. Med. Exp., 1889, 53. 



7. Galippe: C. R. Soc. Biol., 1887, No. 25. 



8. Laurent: Bull. PAcad. roy. de Belg., t. X, 38. 



9. Laurent: Bull. PAcad. roy. de Belg., t. XIX (1890), 468. 



10. Lehmann: Munch, med. Wochen., 1889, No. 7. 



11. Ralph: Trans. Royal Soc. Victoria, Vol. XX, 1884. 



12. Van Tieghem: Bull. Soc. Bot.de France, 1884, XXXI, 283. 



B. On the artificial inoculation of plants with bacteria, non-parasitic in 



vegetable tissue : 



1. Lominsky : On the parasitism of some pathogenic microbes 



for animals in living plants. Wratsch, 1890, No. 6. (Ref. 

 Cent. f. Bakt. VIII, 325.) 



2. Savastano : Tuberculosi delP olivo : Ann. R. Scuola. Sup. 



d'Agric. in Portici, Vol. V, 1887. 



