THE WILT DISEASE OF PIGEON-PRA. 13 
same culture failed in the inoculations of this series. Hence the 
infection could not have come from the culture but from another 
source, probably either from the unsterilised seed or pot-walls or 
from the air. 
Series VII. 
The cultures were subcultures on nutrient agar, rice and onion 
from the rice tube used in the successful inoculation in Series V 
(pot V). 
The plants were fitty consecutive plants in a row in the centre 
of a field plot on the Pusa Farm, and were about 18 inches high. 
The inoculations were made as in Pot I of Series VI. 
No. of plants. | Treatment. ee of inocu- Result. Remarks. 
| ation. 
| 
50 | Inoculated at a wound | 11-8-07. 4 deaths. Perithecia of Neocos- 
| with mixed = agar, | mospora found on 
| rice, and onion cul- | 2 dead plants. 
| tures. | 
Remainder of | Not inoculated. i 7 deaths. Perithecia of Neocos- 
a plot of, (control). | mospora found on 
about 7 one dead plant. 
acre. | | 
J | 
The proportion of deaths in the inoculated row was not 
sufficient, when compared with the deaths in the remainder of 
the plot, to afford proof that the former had died as a result of 
inoculation. 
Series VIII. 
The culture used was obtained by plating ascospores from a 
perithecium on pigeon-pea root, the ascospores being tested and 
found to germinate freely in water. In one plate ten well-isolated 
colonies of Cephalosporium appeared, and all bore perithecia on the 
8th day. From one a subculture was taken on the 5th day, and 
this subculture bore perithecia after four days. From it, when two 
days old, three subcultures were made on glucose agar. These 
were used for the inoculation when eleven days old and with numer- 
ous perithecia. 
