THE WILT DISEASE OF PIGEON-PEA. 15 
for three days, the internal mass being maintained at 100° C. for 
about two hours each day. The seeds were sterilised by steeping 
in ‘1 per cent. formaldehyde for two hours. 
The inoculations were made by sprinkling the seeds after sow- 
ing, but before covering, with the culture broken up in distilled 
water. 
Date of sowing and 
inoculation, Result. 
No. of plants. | Treatment. 
el ee 
26 plants in 4 pots. | Inoculated with a cul- Sown and inoculated | No deaths up to 
| ture on glucose agar. 1-11 0S. 5-38-09. 
17 plants in 2 pots. | Not inoculated (con- | Sown 
trol). 
| 
No difference in growth could be detected between the inocu- 
lated and control pots. All the plants appeared equally healthy. 
SERIES X. 
Attempts were made to infect pigeon-pea with pure cultures 
derived from the ascospores of Neocosmospora obtained from the 
roots of other host plants.' Cotton, indigo, and gram were 
selected. 
The culture used in the case of the cotton Neocosmospora origi- 
nated from a plating of ascospores from a perithecium on the 
root of a wilted cotton plant from Sind. The subcultures were taken. 
from an isolated Cephalosporium colony and bore perithecia in 
about a week. The series was maintained by regular subculturing 
every few weeks, and was fourteen months removed from the parent 
plating at the time of the inoculations below. Every subculture of 
‘the series bore quantities of perithecia. That used in the inocu- 
lation was about a fortnight old. 
In the case of the indigo Neocosmospora some perithecia from 
a wilted indigo (Indigofera sumatrana) plant were well washed 
1 See below, p. 18 ef seg. 
