EELWORM ‘‘ ONION-SICKNESS.”’ 113 
strewed pieces of an infested Onion, and on this we sowed Onion seed, 
and then scattered the right depth of soil. In due time a moderate 
amount of the seed germinated, and (as above noted is the case with 
infested seedlings) scarcely any of the young sprouting plants carried 
the seed husk on the top, and I observed that the abnormal twisting 
or bending was very noticeable,—in the words of my gardener, ‘‘ the 
tops were twisting and curling all over the top of the pot.” 
From the melancholy reason alluded to in my Preface, I was not 
able to give the full attention to my experiment which I should have 
wished under other circumstances, and I did not examine into the 
reason of the gradual dying or disappearance of the young plants. 
But at the end of December I noticed that one little plant was still 
alive. This was about one inch long, and somewhat thickened at 
intervals ; and I cut it into three lengths, and examined these micro- 
scopically by tearing or “‘ teazing’”’ the tissues out with water on a slide. 
In the middle and in one end length I did not find any Eelworms, 
but in the other piece I found several of various ages,—one or two 
apparently quite full grown, the others varying in size down to, 
approximately, an eighth of the length of the largest specimen. The 
parenchyma (or roundish cells of the leaf) were also more separated 
in this piece than in the rest of the plant. 
Thus we secured all the links of the chain of the life-history of the 
infestation in the Onion, besides having an example of the manner 
in which the disease is propagated by passage of Kelworms out of 
infested ground into germinating seedlings. We had the grown 
Onions cracking open from the pressure of the swelled inner scales, 
noticeably swarming with Eelworms, and going on to destruction by 
decay; then by sowing pieces of the infested Onion with common 
Onion seed in earth, in the usual manner, we produced a crop of 
seedlings twisted all about, and without their seed husks on their 
tops; and on examining within, I found the Kelworms present and 
alive on December 30th. 
The stage of disease in the growing plant as shown when about 
six inches high, I had plentiful specimens of from Ashby-de-la-Zouch, 
in which the shortened and widened and also puffed or inflated growth, 
which is characteristic of the Kelworm presence, was very noticeable. 
The attack is considered to be worst to the Onions in their earliest 
life, when, if there are many of the Kelworms in one little plant, it 
will probably entirely fail under their workings. After what may be 
called middle age, the plants suffer less, but still are susceptible of 
attack; and in all stages the infested plants are liable to rapid decay. 
Prevention AND Remepins.—One point is carefully destroying all 
infested Onions. These should be raised (not merely attempted to be 
I 
