110 ONIONS. 
likely infest the land anew. Likewise, in garden ground, it may very 
possibly happen that the infestation may be started by diseased 
Hyacinth-bulbs being thrown to the decay heap; these are very 
subject to the ‘‘ ring sickness,” as it is called in Holland, caused, like 
that of Onions, by 7’. devastatrix. 
On June 11th Mr. Pratt wrote me :— 
‘* Now as to the questions in your letter and suggestions. In my 
ignorance I have allowed infested bulbs to be thrown on manure and 
rubbish heaps. . . . Ialways grow a good many Hyacinths, and 
the bulbs, after flowering, have been thrown to manure or rubbish 
heaps, so that, if any were slightly infested, the arrival of the pest is 
accounted for.” 
Mr. Pratt further remarked that six years ago he left his former 
residence, and ‘‘ brought,” he wrote, ‘“‘with me to this place a quantity 
of Onions, partly to raise seed and partly for use. The bad bulbs 
were again thrown to the manure heap, and so my new garden became 
infested, and wherever I sow Onions, the pest appears. I, of course, 
never sow any crop on the same ground two years consecutively.” 
But with regard to precise detail of starting of the infestation Mr. 
Pratt favoured me with the following very practical note :— 
‘‘ When I came to my present home, my new garden was manured 
entirely with manure brought from an hotel stable, which had not 
been mixed with any rubbish in the way of diseased Onions. In that 
year my Onion crop was perfectly sound; no sign of Helworm. That 
same winter the garden was manured with manure brought from my 
former home, well mixed with diseased Onions as usual. The next 
season my Onion crop was badly affected, and has been ever since.”’ 
In reply to some of my remarks as to the disease being propagated 
by seed from infested Onion plants, Mr. Pratt mentioned that for 
many years he had always used seed of his own saving, but for two 
years he had used seed bought from seedsmen. 
The above observations give a very sound and noteworthy account 
of how, when once the disease is set up, it is continued by the manure 
infested with Eelworms from the diseased Onions mixed with it being 
spread upon the ground; also how, when wninfested manure was used 
in one year to the fresh uninfested ground, there was no attack, but with 
the application of the infested manure in the following season, the 
disease showed itself. 
Where attack is bad, that is, where there are many Helworms in 
the Onion, it dies off; but where there is only a moderate quantity, 
the bulb may grow on, possibly to nearly full size, but almost certainly 
will show the presence of the disease by the outer coats of the Onion, 
which are abnormally thickened, being cracked open and pushed aside 
by the pressing forward of the also enlarged inner growth. 
