Dastur . — The Mode of Infection by Smut in Sugar-cane . 393 
If the bud to be inoculated was covered by the leaf-sheath, the latter 
was completely removed without injuring the bud. All the experiments 
had controls which invariably remained healthy. 
Two very tender buds of a potted plant were inoculated by means of 
spores on June 22, 1918. About two months later, August 15, the shoots 
developing from these inoculated buds had produced the characteristic 
spore-bearing whip-like prolongations. Three days later the shoot from 
below the inoculated bud was also smutted. Microscopic examination of 
the plant showed that its tissues were filled with smut hyphae. 
Plants inoculated through wounded roots and root buds remained 
healthy and no hyphae were found in 
their tissues. 
The crowns of a few plants were 
cut back without injuring the growing- 
points and the tops of a few plants 
were completely removed, and the 
cut ends were inoculated with spores 
and with cultures on bread meal. All 
the infections failed. 
On August 27, 1918, several 
plants were inoculated through tender 
wounded and unwounded buds. A 
month later sections were made of 
the small shoots arising from some of 
the inoculated buds. Smut hyphae 
were found in the growing-point and 
in the scale leaves. On November 
6, one of the inoculated buds gave a 
spore-bearing shoot. After this date 
spore-beariffg shoots were produced 
from time to time till April 1919. 
One of the plants had all the in- 
oculated buds except one removed for 
microscopic examination. The uninoculated buds below and above the 
inoculated buds gave smutted shoots. The whole cane was found to contain 
smut hyphae. Some of the adventitious roots arising from nodes above 
ground level were found to have their cortical tissues infected with smut 
hyphae. 
One plant (Fig. 1) had only one bud (B) inoculated on August 27, 1918. 
This bud remained dormant till April 9, 1919, when it was sectioned and 
was found to contain smut hyphae in its tissues. The mycelium from the 
inoculated bud entered the node and travelled up and down the stem, and 
from the stem passed into the other buds. The smut hyphae in the main 
Fig. 1. Inoculated sugar-cane plant, for 
explanation see text. 
