394 Das tar . — The Mode of Infection by Smut in Sugar-cane. 
stem was traced right up to the growing-point. The bud (c) on the node 
immediately above the inoculated bud showed signs of sprouting in the 
beginning of January 1919, and it died in the end of March. No spore- 
bearing whip was produced. The bud (d) on the node above this dead 
shoot began to open in the middle of March and on April 10 developed 
a spore-bearing shoot. The bud (a) below the inoculated dormant bud was 
seen to burst in the beginning of March, and on April 6 the characteristic 
spore-bearing shoot was visible. Rootlets arising from this node and from 
the node below it had smut hyphae in their cortical tissues. 
At times the inoculated bud dies before it has grown into a shoot. In 
this dead bud are found smut hyphae ; they can also be traced into the node 
and in the internodes above and below this node. The extent of the pene- 
tration of the hyphae depends upon the time that elapsed since the inocu- 
lation. 
A ‘ thick’ variety of cane, Purple Mauritius, was inoculated on January 
13, 1919, through wounded buds. Some of the shoots from the wounded 
bud were sectioned on April 26; smut hyphae were found in their tissues. 
Inoculations through unwounded young and old buds were unsuccessful. 
Another ‘thick’ variety, Sathi 131, was inoculated through wounded and 
unwounded tender buds on July 1, 1919, and the cuttings were incubated in 
moist chambers. On the 23rd, the shoots from all the wounded inoculated 
buds were found on microscopic examination to be infected, but the shoots 
from the unwounded inoculated buds showed no signs of infection. , 
On April 10, 1919,(1) unwounded old buds, (2) wounded old buds, 
and (3) unwounded tender buds were inoculated with cultures of the smut 
on bread paste. Five weeks later some of the buds from each of these 
series were sectioned and microscopically examined ; smut hyphae were 
found in the inoculated wounded old buds and in the un wounded tender 
buds, but not in the unwounded old buds. 
Some of the unwounded tender and wounded old buds inoculated in 
August and November 1918 remained dormant, and the plants did not 
show any external signs of infection. These plants were cut into setts and 
those setts which had the dormant inoculated buds were planted in five 
pots on March 28, 1919. On April 20, a smutted shoot was produced by 
one of these setts, the buds of which were inoculated without wounding 
them on November 28. Two setts, which had unwounded inoculated buds, 
gave smutted shpots on June 18 and September 7, 1919. A fourth sett, 
which had wounded inoculated buds, was found smutted* on June 19, 1919, 
and the fifth sett developed a smutted shoot on November 15, 1919. One 
plant was inoculated through its buds by wounding them on January 13, 
19 T9. The inoculated buds were dormant on April 28, when a cutting from 
this plant with the dormant inoculated buds was planted. On June 17, 1919, 
one of the shoots was found to produce a spore-bearing ‘ whip ’. 
