52 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Wisley in July last, a small exhibit was arranged in the laboratory, and 
I then expressed the opinion that eelworm was probably the cause of 
the trouble, but inoculation experiments were necessary before any 
definite statement could be made. These have since been carried out. 
Bulbs attacked with the eelworm disease exhibit certain symptoms 
which are now well known and easily recognizable. No one symptom 
can be regarded as definitely characteristic of the disease. The 
disease may show itself in the bulb, or in the foliage, or both. The 
fleshy scale leaves, sometimes one, at other times a number, of an 
infected bulb, show a distinct brownish colour, and when the bulb is 
cut across horizontally the diseased scale leaves take the form of rings 
(fig. 17) ; hence the name " ring disease " which is a descriptive and 
suitable popular name for the disease. It is in this brown mass that 
eelworms in all stages of growth are readily discernible when the 
tissue is teased and examined under the low power of the microscope. 
The bulb may be so affected that the growing scales and embryo flower 
are diseased. If so, the bulb when planted, if it grows at all, throws 
up sickly yellow foliage which twists and turns in all directions (fig. 18). 
The leaves are silky and spongy in texture and marked with long 
brownish diseased areas, at times running along the whole edges of 
the leaves, while irregular whitish eruptions caused through the break- 
ing of the epidermis may appear (fig. 19). The flowers resulting from 
such bulbs are stunted in growth, as the photograph (fig. 20) clearly 
illustrates. The growth of diseased bulbs is generally much retarded 
as compared with that of healthy bulbs, but the extent of this depends 
upon the degree of infection. Healthy bulbs and diseased bulbs of 
the same variety were planted in pots, grown in cold frames, and 
given exactly the same treatment. The healthy bulbs flowered at a 
time when the diseased bulbs had made but an inch or two of growth 
(fig. 21). 
In cases where the bulb is but slightly diseased, the growing leaves 
and flower may be unaffected. The foliage then appears, and probably 
is, perfectly healthy, so that though the leaves show no signs of the 
disease, it does not necessarily mean that a healthy crop of bulbs 
will be harvested. It may be regarded as certain, where sickly, 
deformed yellowish foliage is seen, even when an inch or two of growth 
has been made, that the bulb is affected, and no time should be lost 
in carefully removing it. 
After many failures, a method was devised by which Tylenchus 
could be successfully isolated and grown in pure culture, and inocula- 
tion experiments were commenced without delay. On September 7 
a few eelworms were pricked into the necks of healthy bulbs by means 
of a sterile needle, and the bulbs planted in steam-sterilized soil in 
pots and stood in a cold frame, where they remained throughout the 
experiment. Control experiments were arranged, healthy bulbs being 
grown in sterilized soil, the necks pricked with a sterile needle, but 
no eelworms introduced. On February 19 (six months after inocula- 
tion) the bulbs were lifted, and eelworms, which were found in all 
