338 PLANT DISEASES 



BRUNISSURE 



In Europe and North America a disease of the vine, 

 characterised by the appearance of brown spots on the 

 leaves, which eventually extend, and cover more or less the 

 entire surface, has been considered by Viala and Sauvageau, 

 as due to the presence of an amoeboid organism in the 

 cells, to which they have given the name Plasmodiophora 

 vitis, Viala and Sauv. 



The California vine disease is also considered by these 

 authors to be caused by an organism allied to the last, 

 which they named Plasmodiophora californica, Viala and 

 Sauv. 



I have demonstrated elsewhere that Brunissure, also 

 the disease on the leaves of cultivated orchids, known as 

 ' spot disease,' is entirely due to physical causes. 



Viala and Sauvageau, Journ. de Botanique, 1892, figs. 

 Viala, Malad. de la Vigne, ed. iii. 

 Massee, Ann. Bot., vol. ix. p. 421, i pi. 



BACTERIA 

 BACTERIOSIS OF TOMATOES 



Prillieux has described a bacterial disease of tomatoes, 

 which is very destructive in the north and central parts of 

 France ; it has also occurred in England. 



Inoculation is supposed to be effected through the style 

 of the flower, and from this point a blackening of the fruit 

 extends in circles until the whole is destroyed. 



Prillieux, Malad. des Plantes Agric., vol. i. p. 19, fig. 



