72 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
The Effect of Treating Bulbs with Poisonous Gases. 
Healthy and diseased bulbs were fumigated in air-tight chambers 
with toluol, carbon-bisulphide, formaldehyde (the gas being generated 
by the action of potassium permanganate on commercial formalin), 
hydrocyanic acid, naphthalene, and nicotine. The results are set forth 
in Table III. 
Table III.-— The Effect of Fumigating Healthy and 
Diseased Bulbs. 
Gas. 
Length 
of Fumi- 
gation. 
Effect on Growth 
oi xieanny rJuius. 
Condition of Eelworms 
in Bulbs. 
JNaphtnalene 
I day 
no injurious enect 
V 
eelworms found alive 
> > • 
2 day^ 
" " " 
" . * 
4 >> 
7 „ 
„ 
>> >> »> 
Formalin . 
i day 
2 days 
>> >> j> 
4 „ 
>> >> >> 
7 » 
>> >> ») 
Toluol 
i day 
>> >> >i 
... 
a. days 
>> >> ») 
... 
4 >, 
y> >> >> 
> y 
7 \ v 
Carbon-bisulphide 
i day 
>> >> >> 
)> 
2 days 
>> >> »> 
>> 
4 » 
>» >) >> 
>> 
7 >> 
>> »> >> 
Nicotine . 
i day 
2 days 
4 » 
>> ... 
7 >, 
>> >> >> 
Hydrocyanic acid 
i day 
>> ft ft 
>> 
2 day^ 
slightly damaged 
>> >> >> 
4 „ 
damaged 
>> >> >> 
>> • 
7 » 
badly damaged 
Fumigation appears to be of no use in killing the eelworms 
in affected bulbs, and it is probable that the bulbs offer the same 
resistance to the entrance of gases as they do to the admission 
of solutions. 
Effect of Heat on Eelworms. 
Experiments were conducted with the Reichert Thermal Stage, 
by means of which apparatus it is possible to maintain a constant 
temperature during examination under the microscope. The eel- 
worms, isolated from diseased bulbs, were placed in direct contact with 
the warm stage. The results are shown in Table IV. on page 73. 
The ease with which eelworms could be killed by direct heat led 
the writer to believe that soaking the bulbs in warm water might lead 
to a possible means of control. 
Reference has already been made to work carried out by Mr. 
Hewitt and Mr. Barr on the soaking of bulbs in warm water, and, 
