51 



NOTE ON BACTERIAL DISEASES OF THE ROOTS OF 

 THE LEGUMINOSuE. 



By Thos. L. Bancroft, M.B., Edin. 



(Communicated hy J. H. Maiden, F.L.S.) 



(Plate iv.) 



AVhilst transplanting some sensitive plants {Mimosa pudica, 

 Linn.), my attention was attracted to the peculiar tuber-like 

 bodies on their roots, which were distinct from the tubercles 

 caused by worms (Tylenchus). 



When broken across these bodies were noticed to possess a juice 

 having a remarkable smell ; microscopic examination showed this 

 fluid to be teeming with bacteria, all in a state of violent agitation. 

 Cover-glasses were smeared with it, passed through the flame and 

 stained in methyl-blue ; examined both in the wet state and after 

 clarifying and mounting in balsam, the bacteria were seen to be 

 bacilli. Search was made for a similar disease in other plants, 

 but only speciuieiis of the Leguminosce were found affected, indeed 

 every plant examined of that order had a bacterial disease. The 

 tubercles on the roots exhibited great variety of shape, as did also 

 the bacilli contained in them ; some of the latter were very thin 

 and long, others thick, some curved, many were motile, some 

 iinmotile, whilst others exhibited Brownian movements; all appa- 

 rently were referable to the genus Bacillits. 



No Leguminous plant appears to be altogether free from a 

 bacterial disease of the roots ; some genera, however, are affected 

 more than others. I have so far not noticed a similar disease on 



