THE WILT DISEASE OF PIGEON-PEA. 11 
A plating from one of these sprouting perithecia was made on 
April 7th, 1907, and several of the resulting colonies bore peri- 
thecia in turn. From one of these perithecial colonies, well isolated; 
a trace of aerial mycelium bearing Cephalosporium spores was again 
plated and good isolated colonies originating from a single spore 
were obtained. Subcultures were made from one of these colo- 
nies which was marked and showed perithecia a few days after, the 
subcultures were obtained. The media were boiled pigeon-pea 
slabs, carrot, onion, boiled rice and plantain. 
The plants were grown in pots, the earth in which was sterilised 
by intermittené steaming on three days in the Koch. The soil was 
damped and packed loosely into perforated kerosine oil tins. Un- 
der these conditions the interior of the mass reached about 87° C. 
after two hours’ steaming, and was kept at this temperature for 
about three hours each day. Higher temperatures were not 
obtained with the ordinary Koch steriliser, but the above may be 
taken as sufficient to kill all life, but the most heat resisting 
bacteria in soil. Subsequently (in 1908) a Hearson’s thermostatic 
dry steam steriliser was used and a temperature of 100° C. 
throughout was easily reached with this. The soil was loaded 
into twelve unsterilised pots, in each of which about twenty-five 
unsterilised seeds were sown. Germination was good. 
The inoculation was made by sprinkling the soil with the cul- 
ture broken up in distilled water just after the plants were up. 
No. of pot. Treatment. Date of inoculation. Result. Remarks. 
I | {noculated with culture 11-5-07. No deaths. 
on pigeon-pea slab. 
II ” PB) F | ” 9 ‘9 ” 
III 9 99 ” carrot ” ” ” 
ins he La | on ONION 99 
V * ve 5, Vice a Wiltappeared. Two plants wilted 
VI ; plantain 20-5 07. No deaths. on July 3rd. All 
VIL ‘|Not inoculated (control) a “p rr were dead but 
VIL Ee Be ee ne one on August 
IX i = Lacy anges 14th. 
x 3° pave ” ” | 
XI ” deh %”9 ” 
IT ” oo ” ” 
