444 G. P. DARNELL-SMITH. 
flavour in the product. Cultures frequently become slimy or ropy 
on propagation. Thisis not necessarily due to contamination with 
specific slime-forming organisms but rather to a change in the 
lactic organism itself. Such an abnormality usually persists for 
a short period only, and the conditions that govern its appearance 
and disappearance are not known.” 
Too much reliance therefore for the purposes of identifica- 
tion cannot be placed upon the reactions with the sugars 
of any organism unless it has been freshly obtained. 
While in tomato plants from Emu Plains showing 
undoubted signs of wilting, bacteria have been found in 
countless numbers in the cells, and which were easily visible 
in the cells in sections, in the tobacco plants that I have 
examined the bacteria are not easily visible in sections. 
Yet from diseased plants from Tamworth, from Barraba, 
and from Texas (N.S.W.) it has been possible to obtain with 
ease what were apparently pure plate cultures. Bact. 
solanacearum apparently exists in our soils, and my view 
at present is that the wounds in the stem caused by the 
rotting leaves of the seedlings attacked by Peronospora 
hyoscyami afford a means of entrance to the bacteria into 
the plant. Ifa series of sections be taken across young 
plants attacked by Peronospora hyoscyami,apoint or points 
will be found where a connection is visible between the 
decayed end of aleaf and the brown discoloured vascular 
System of the stem. In some few roots I have found eel 
worms, but they have not been found sufficiently often to 
suggest that they make a wound through which the bac- 
teria enter. The method followed of obtaining cultures 
has been to isolate a very small piece of the diseased 
tobacco stem under strictly aseptic conditions, to place 
this piece in broth and then to pour agar plates from the 
broth. 
The plates obtained have been always apparently pure 
cultures. The colour of the colonies varies from white to 
