107 
ON.LOWNS. 
Eelworm “Onion-sickness.” Tylenchus devastatrix, Kuhn. 
ed 
Eelworm-sick Onion, the outer scales cracked open by the swelled growth of the 
inner infested scales. 
On June 9th I received a number of young Onion plants much 
deformed in growth, and infested within by the Stem Helworm, 
Tylenchus devastatrix, which we know best in this country as causing 
“Tulip-root’’ in Oat plants, and ‘‘Stem-sickness’”’ in Clover, and 
which has been well known for about twelve years in Holland as 
causing the disease known as Kelworm ‘ Onion-sickness.” Probably, 
now that attention is directed to it, we shall find that the disease is 
very widely distributed here, and is often the cause of the cracking 
open of Onions, or total failure of the crop (for no known reason) on 
some special piece of ground; but up to date of the specimens being 
sent me, I am not aware of the attack having been observed, or at 
least brought under technical notice, in this country. 
On June 9th I was favoured with the first observations by the 
Rey. Charles Pratt, from The Elms, Ashby-de-la-Zouch, Leicestershire, 
Specimens being sent accompanying, of which Mr. Pratt observed :— 
‘“‘My gardener assures me that it is not the Onion Maggot, but it 
is a very severe scourge. The neck of the stalk just above the bulb 
begins to swell, and the swelling increases (if the plant is left alive) 
very considerably until it becomes a soft pulpy neck, and the bulb 
