EELWORM ‘‘ ONION-SICKNESS,”’ 115 
applicable, namely, burning diseased plants, only sowing good seed, 
or steeping what may be infested, and substituting crops not liable to 
Kelworm infestation for a time. As above mentioned, good manuring 
to help the plants over moderate attack is also important. 
How the attack came into my own garden I am wholly unable to 
say. I did not see a sign of it in the bed with my crop of summer 
Onions; nor in the rows of seedlings sown in autumn for next year’s 
supply could I say that there was a trace amongst the thousands of 
plants, all these being (so far as I am aware) entirely sown from the 
same bag of seed. I found the disease only on the one patch named, 
and in seedling Onions raised in earth mixed with pieces of infested 
Onion from this patch. My only explanation is that, as I am 
frequently in receipt of specimens of Tulip-rooted Oats and Stem-sick 
Clover, by accident some of the specimens, instead of being carefully 
destroyed, were thrown aside in the garden, and that thus the Hel- 
worms (7’. devastatriz) within made good an establishment. 
The above notes give some idea of the characteristics and serious 
nature of Onion-sickness, that is, of Eelworm attack in connection 
with Onions, for which (excepting such matters as I have myself 
become acquainted with in the course of the past year) I am indebted 
to the excellent articles of Dr. Ritzema Bos, given in his ‘ Anguillule 
de la Tige,’ and more recently still in his ‘ Tierische Schadlinge und 
Nutzlinge.’ 
For descriptions and means of prevention of attack of the same 
species of Helworm, namely, 7'ylenchus devastatriv, in connection with 
Oats and Clover, the reader is referred to the preceding paper on 
“Stem Eelworms,”’ at pp. 44-52. 
Should any readers have doubts whether their Onions are suffering 
from this attack, or should desire more detailed information, I would 
gladly examine microscopically, and give my best attention. Only, as 
decaying Onions trench a little on what is admissible for postal trans- 
mission, I would beg them not to send more samples than necessary, 
and to secure them by safe wrapping or packing in a tin. 
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