466 Journal of Agricultural Research 



Vol. V, No. IX 



and isolated a yellow schizomycete with which unsuccessful inoculations 

 were made on cucumbers in the Department greenhouses. 



ISOLATION AND IDENTIFICATION OF ORGANISM 



Specimens were sent to the Laboratory of Plant Pathology in August 

 and September, 1914, from New York and Wisconsin. No complaint 

 was made by the sender of any association with fruit-rot, either on his 

 own initiative or when questioned. 



The interior of the spots was found to be swarming with bacteria 

 which on floating out on the slide showed active motility. Plates were 

 poured from such spots and a white, motile, rod-shaped organism was 

 isolated. Spray inoculations with subcultures from three colonies on 

 these plates gave typical infections on young cucumber leaves, from 

 which the organism was reisolated. Colonies (subcultures) from this 

 reisolation were then used for spray inoculations, and again the typical 

 disease was produced with great virulence. 



In August, 1 91 5, specimens were received from several localities in 

 Wisconsin, Indiana, and New York and from Ontario, Canada. In 

 each case the same organism was isolated in pure cultures and used to 

 produce typical infections on cucumber leaves in the hothouse. 



The organism causing the angular leaf-spot of cucumbers appears to be 

 an undescribed form for which the specific name lachrymans is suggested 

 on account of the tearlike drops of exudate from^the spots in early stages 

 of the disease. Its brief Latin diagnosis is as follows: 



Bacterium lachrymans, sp. nov. 



Baculiscylindricisapicibusrotundatis, solitariis, saepe binis; baculisunis 0.8X1-2/1; 

 1-5 flagellis polaribus mobilibus; aerobiis, asporis. 



Habitat in foliis vivis Cucumeris sativi in maculis angularibus. Liquefacit gela- 

 tinam lente. Colonae superficiales in agar-agar, rotundae, albae; colonae juvenes 

 habientes centra non-translucida, et margines translucidas cum lineis multis radianti. 

 bus. Lac sterile alkalinum et translucidum fit; casein non segregatur. Nitrum non 

 redigitur; culturae in mediis cum saccharo sacchari et saccharo uvae acidae fiunt. 

 Gas non facitur. Methodo Grarai non coloratur. 



The organism which the writers isolated from the Wisconsin cucumber 

 leaves and have here designated "Bacterium lachrymans, n. sp. " differed 

 culturally is so many important respects from Burger's organism that 

 all our cultural experiments were repeated. These repetitions, however, 

 confirmed the differences, which are given in Table I. 



While it is not doubted that Burger had this disease under observation, 

 it is believed that the organism described by him is not its cause, but is 

 rather the cause of a rapid soft-rot of the fruit. His organism, however, 

 may be a wound parasite following injuries due to the organism here 

 described. 



