1899] BRIEFER ARTICLES 67 
taken to avoid the introduction of foreign microbes. I used Dr. 
Roux’s sterilizable syringe with a fine injection needle, in order to 
reduce to the minimum the wound necessary for the introduction of 
the culture. Only the stems were inoculated. The epidermis was 
exposed by cutting a small flap in the leaf sheath, carefully disinfecting 
by means of a red-hot iron, and, after the inoculation, the opening sealed 
by means of warm wax or sterilized paper. The plants experimented 
upon were successively examined at intervals of time varying from five 
days to two months. In every case the yeast had developed and mul- 
tiplied in the intercellular spaces, and in the interior of the living 
cells to a distance of 10 to 1 5™" above and below the point of inocu- 
lation. 
The microscopical appearance was that which may be observed in the’ 
tissues of sorghum spontaneously infected ; the lesion was also rend- 
ered visible in the same way by the red coloration of the parenchyma 
and fibrovascular bundles. These latter transfuse the coloring matter 
the whole length of the internode, and quite beyond the infected 
region, so that the appearance of the pigment at a certain point of the 
tissue is not a sure sign that the parasite is present at that point. On 
the surface of the stem may be observed long red lines corresponding 
to the outer bundles and their contiguous parenchyma seen through 
the transparent stem. 
In these experiments, the isolation of the parasite from the affected 
pith has shown, by comparison with the control, that the parasitic 
Yeast was the same as that in the cultures used as a starting point. 
t is probable that the reserve sugars of the cells of the sorghum 
“onstitute the principal food of the parasite. Unfortunately the volume 
of infected tissue, limited and especially difficult to separate out, has 
not permitted the changes carried on by the parasite in the chemical 
“omposition of the plant to be estimated in this particular. 
= Jaa capable of producing in aie sorghum similar phe- 
Eade a ? The following experiments answer’ th the 
healthy = oo have been made ‘aseptically in the stems of 
chatnpagne't ta with pure cultures of wine yeast (round yeast of 
‘5 pee: Owzy]). The parasitism has been established under the 
sacs ky oy a before, the yeast developing in the intercellalar 
€ pith cells of the stem with the accompanying produc- 
tion =e : 
be Of the characteristic red pigment, and with transfusion by the 
Ndles of the internode. 
