108 ONIONS. 
(which Zooks much like a good one) is quite soft and squashy. The 
roots mostly perish, and the plant comes up with the slightest pull. 
The diseased Onions are mostly in patches, and often all down the 
middle of the bed, far more than at the ends. I have suffered for 
many years, and if you wiil tell me what to do, I shall be very 
grateful.’ —(C. P.) ; 
The specimens sent were about thirty in number, ranging from five 
to six inches high, and gave excellent examples of different early forms 
of diseased growth caused by presence of Stem Kelworm (T’. devastatriz). 
In one form the general growth was distorted, and the large leaf 
or flag swollen, and at one side of the bulb were mis-shapen side 
growths, these again throwing out other small pointed side growths, 
more resembling the branching of roots than normal leaf growth of 
bulbs. In another form the distorted malformed shoots from the base 
of the bulb were almost like curved flat claws, and turned downwards 
into the ground; in yet another form, instead of being of the tapering 
shape of a healthy young Onion-bulb, it was more like a square knob. 
The distorted growths from the base of the bulb strongly resembled, 
both in their pale yellowish colour and their bent narrow growths, 
those often noticeable round the bulb-like swelled base of Tulip-rooted 
Oat plants. 
The tumid swelled growth of one or more of the leaves of the 
diseased young Onions was a very frequently observable characteristic ; 
and inside the bulbs of the infested plants I found the Eelworms in 
great numbers. Many of these Nematodes were still quite young,— 
by estimate, some of them were hardly an eighth of the length of the 
largest specimens, in some I was able to detect the spear and its 
bulbed base in the gullet (see Plate), which is to some degree a 
characteristic of this kind of Kelworm. 
These Nematode-worms being at full growth only about one-twenty- 
fifth of an inch in length, and one-thirty-second part of their length 
in width, it is almost impossible for any ordinary observer to make 
out trustworthily the minute points of structure which are the specific 
characteristics of these little wormlets. Therefore, in order to be 
absolutely certain of the species, I forwarded specimens to Dr. J. 
Ritzema Bos, Director of the Phytopathological Laboratory at Amster- 
dam, and the great authority on this kind of infestation, who was good 
enough to examine the Helworms, and pronounce them to be without 
doubt Tylenchus devasiatria. 
At p. 45, in the foregoing pages, will be found a few lines of 
description of this Nematode and its life-history ; and at p. 47 a figure 
of distorted growth at the base of the stem of a Tulip-rooted Oat plant 
caused by the same species of Helworm, which gives an idea of the 
growth sometimes to be found round the Kelworm-sick bulb. 
