SCHIZOMYCETES. BACTERIA 107 



The flagella in many species are relatively evanescent, or produced 

 at a definite period, so that the time of motility may be brief. The 

 cells are more commonly united into short threads than in the case 

 of the preceding genus. Endospores are frequent. Among the 

 species of much importance may be mentioned the following : 

 Bacillus amylovorus Burrill, Bacillus tracheiphilus Erw. Smith, 

 Bacillus carotovorus Jones, Bacillus aroidece Townsend, Bacillus 

 solanacearum Erw. Smith, Bacillus Hyacinthi-septicus Heinz, 

 Bacillus Cubonianus Macch. 



II. BLACK ROT OF CABBAGE 

 Pseudomonas campestris (Pammel) Erw. Smith 



CARMAN, H. A Bacterial Disease of Cabbage. Ky. Agl. Exp. Sta. Rept. 3 : 



43-46. 1890. 

 HARDING, H. A. Die schwarze Faulnis des Kohls und verwandter Pflanzen, 



eine in Europa weit verbreitete Pflanzenkrankheit. Centrbl. f. Bakt. Par- 

 ask., u. Infektkr. 6(11. Abt.): 305-313. 1900. 

 HARDING, STEWART, PRUCHA. Vitality of the Cabbage Black Rot Germ on 



Cabbage Seed. N. Y. Agl. Exp. Sta. Built. 251 : 177-194. 1904. 

 PAMMEL, L. H. Bacteriosis of Rutabaga (Bacillus campestris n. sp.). Iowa 



Agl. Exp. Sta. Built. 27: 130-135. pi. i. 1895. 

 RUSSELL, H. L. A Bacterial Rot of Cabbage and Allied Plants. Wis. Agl. 



Exp. Sta. Built. 65: 1-39. figs. 1-12. 1898. 

 SMITH, ERW. F. Centrbl. f. Bakt. Parask., u. Infektkr. 3(11. Abt): 284-291, 



408-415, 478-486. pis. 1-6. 1897. 

 SMITH, ERW. F. The Black Rot of the Cabbage. U. S. Dept. Agl., Farmers' 



Built. 68: i -2 1. 1898. 

 SMITH, ERW. F. The Effect of Black Rot on Turnips. U. S. Dept. Agl., 



Bureau of Plant Industry, Built. 29: 1-19. pis. 1-13. 1903. 

 STEWART, F. C, and HARDING, H. A. Combating the Black Rot of Cabbage 



by the Removal of Affected Leaves. N. Y. Agl. Exp. Sta. Built. 232 : 



43-65. pis. 1-2. 1904. 



Habitat relations. In recent years this cabbage disease has be- 

 come well known as the most destructive and least controllable 

 cabbage disease. It has been very generally reported from the 

 states of the Mississippi Valley and eastward, extending into 

 Canada as well. It is also well known in Europe. Possibly a form 

 of the same disease may occur in Japan upon radishes. 



It has been shown that infection takes place by way of the water 

 pores of the host. In accordance with this fact, the climatic con- 

 dition favoring the entrance of the organism is sufficient moisture 

 in connection with warm days and cool nights. This would favor 



