CONTRIBUTIONS FROM THE WISLEY LABORATORY. 67 
order to avoid the great possibility of planting healthy bulbs, which 
are generally present in larger or smaller number* in an infected 
stock. The healthy stocks were treated in the same manner to make 
certain that no diseased bulbs were present in the stock classed as 
healthy. By this means, as far as it was possible to ascertain, all 
bulbs classed as diseased were affected bulbs, while those placed under 
the heading of healthy were free from eelworm attack. 
Twelve diseased bulbs and the same number of healthy ones 
were treated in each case, and planting was carried out in November 
1916. In May igiy.the bulbs were lifted and the diseased ones micro- 
scopically examined to ascertain the effect of the solution on the 
eelworms. 
Table II. presents the practical results of these tests, showing the 
duration of the time of soaking, the effect of the solution on the growth 
of the bulb (this being ascertained from the behaviour of soaked healthy 
bulbs), and the effect of the solution upon the eelworms. Eighteen 
hours were taken as the minimum period of soaking, as it was con- 
sidered improbable that a solution could enter the bulb sufficiently 
to be injurious to the eelworms in less time. All the bulbs were 
treated in glass vessels and were planted directly after treatment. 
Table II. — The Effects of Soaking Healthy and 
Diseased Bulbs in Chemical Solutions. 
Strength of 
Period of 
Effect on Growth of 
Condition of Eelworms 
Solution. 
Soaking. 
Healthy Bulb. 
in Bulbs. 
Creol 
i per cent. 
18 hrs. 
no injurious effect 
live eelworms 
found 
>> 
24 „ 
>> 
>> 
»> 
48 „ 
>> 
72 „ 
99 
>> 
96 „ 
Creol 
2 per cent. 
18 „ 
99 
>> 
24 „ 
48 „ 
>> • 
>> 
>» 
>> 
72 „ 
99 
very slightly 
damaged 
»> 
>> 
96 „ 
,9 
Creol 
4 per cent. 
18 ,, 
slightly damaged 
j) 
24 9 9 
damaged 
> > 
48 „ 
badly damaged 
}> 
72 „ 
99 
tt 
96 „ 
99 
Creol 
6 per cent. 
18 „ 
>> 
99 
>> 
24 99 
99 
»' 
)> 
48 „ 
>> 
> j 
72 
bulbs killed 
99 
> > 
96 „ 
Copper sulphate 
5 per cent. 
18 „ 
badly damaged 
>> 
24 9, 
48 „ 
99 
> ) 
> > 
72 „ 
99 
9 9 
>> 
96 „ 
99 
Copper sulphate 
7|per cent. 
18 „ 
> .< 
> > 
24 99 
9 9 
)) 
48 „ 
99 
