46 THE GUMMOSIS OF THE SUGAR-CANE. 



Ordinary luitrletit-agar stroke. — A slow-growing thin, yellowish 

 white glistening stroke. 



Glycerine niitrient-agar stroke. — A thin, broad, translucent 

 white, moist, glistening growth, with turbid condensed water. 

 The colour deepens to a primose-yellow. 



Saccharose {lOy^Yj'yeptone {0'iy^)-agar. — A thin white fluid 

 growth, which gravitates into the condensed water, in which 

 there is a yelloAv sediment. 



Potato. — A primrose-yellow, moist, glistening growth, some- 

 times raised and restricted, at other times flat, watery, and 

 spreading over the surface. Compared with agar or gelatine, 

 the growth is rapid. 



Carrot. — A raised, slimy, yellow growth, at tirst restricted, but 

 eventually covers the surface and gravitates. 



Turnip. — As on carrot. 



Sugar-cane. — No visible growth. 



Nutrient houillon. — Slights turbid fluid, with faint indol re- 

 action. 



Nitrate bouillon. — There is no reduction of the nitrate. 



Siveet ivort. — No growth. 



Cane-juice. — No growth. 



Milk. — Unaltered ; neutral reaction. 



The Affinities of the Bacterium. 



Since the organism does not form colonies on gelatine which 

 throw out processes from the margin, it is not jBact. gummis to 

 which Comes ascribes the gummosis of the vine. Bad. ajni, said 

 to produce a disease in celery, is larger, and grows more slowly 

 upon potato, but otherwise there are points of similarity in the 

 appearance of the colonies on gelatine, which, however, are 

 white as against the j'ellowish colour of Bact. vasculanim. 

 Basse's bacteria produce gas in glucose media, and otherwise 

 differ. Bact. tracheiphilus, a bacterium which causes the wilting 

 of some of the C^icurbitacece by plugging the vessels, differs in 

 colour (white), and by forming very ropy cultures in fluid media, 

 especially when old. Arthur and Golden have described Bact. 



