PLANT BACTERIA-VOL. 3. 



PLATE 23. 



V 



13 



1 



TOBACCO WILT. POTATO DISEASE. RATHAVS DISEASE. 



(1) Litmus-milk culture, 12 days old, of Bacillus solanisaprus I. Painted March 19, 1907. (in) Litmus-milk culture 12 days. 

 old, of Bacillus phytopMhorus. Inoculated and painted at same time as fig. 1. (2) Old browned colonies on the surface of an agar 

 plate of the N. C. tobacco organism, poured August 1, 1905, painted October 14; agar stained brown. (3) Litmus-milk culture of 

 Appel's Bacillus phutopMhorus. Tube inoculated November 13", 1906. Painted November 26. (4) Uninoculated (check) tube of 

 litmus-milk. (5) Bacillus solanisaprus Harrison I. An old litmus-milk culture kept in the refrigerator (14C.) and partly dried out. 

 Inoculated December 10, 1906; painted March 4, 1907. (6) Old potato-culture of Bacillus phi/tnphthorus Appel. Stock 1975, painted 

 March 5, 1907. (6) Potato-culture of Bacillus solanisaprus Harrison II. Inoculated March 7, 1907, and painted March 19. The 

 color close, but the organism wet-shining. (7) An old litmus-milk culture of Hurl, solanacearum, Florida potato, tube inoculated June 2, 

 1905, painted August 28 and equally representative of an old culture of the N. C. tobacco organism. (8, 10) Cross-sections of 9 and 11, 

 showing the characteristic bacterial decay. (9, 11) Internally brown rotted potato tubers from Portsmouth, Va., painted October 18-19, 

 1905. Infection by way of the vessels of the rhizome; the surface of the tuber not ruptured; Bad. solanacearum very abundant in 

 the vascular system of rhizomes and tubers. (12, 13) Aplanobacter rathaj/i; milk and litmus-milk, 5 months. 



