THE FUNGI WHICH CAUSE PLANT DISEASE 31 



In 1894 Boyer and Lambert ^^ produced successful inoculations 

 on mulberries with an organism to which they gave the above 

 name, but without description. 



In 1908 E. F. Smith, ^' plated out, from blighted mulberry 

 leaves collected 

 in Georgia, a 

 white species 

 with which he 

 made numerous 

 infections on 

 both stems and 

 leaves of mul- 

 berry. From 

 these cultures 

 Smith supplied 

 the description 

 quoted in part 

 above. The re- 

 1 a t i o n which 

 Bacillus cuboni- 

 anus '"^ has to 

 this mulberry 



r^;t.oQC!o io iin Fig- 17- — Ps. medicaginis; agar colonies 7 days old, deep 

 Uisease ib uii- ^^^^ surface colonies by reflected light. After Sackett. 



known. 



Ps. phaseoli E. F. Sm. A short round-ended rod, wax-yeUow 

 to chrome; motile; anaerobic. Milk coagulates, and the whey 

 slowly separates wathout acidity ; gelatine liquefies slowly. Growth 

 feeble at 37°, none at 40°. T. D. P. 10 min., 

 49.5°. A starch enzyme is produced and the 

 middle lamella also dissolved. 



This organism is pathogenic to beans and 

 some related legumes and is closely related to 

 Ps. hyacinthi and Ps. campestris. The bean 

 Fig. 18.— Ps. phaseoli. disease, occasioned by it was noted and as- 

 After Snaith. ^^.^^^ ^^ bacteria by Beach '"' and by Hal- 



sted ^° in 1892, and the organism was described by E. F. Smith 

 in 1897 " after it had been grown in pure culture and successful 

 inoculations had been made. 



