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incriminate the species. Plants are commonly half grown or bear- 
ing fruit before they are noticeably weakened by the eel-worm. 
The young eel-worm (Fig. 19) is very minute and elongate. 
It is provided with a spearlike organ projecting from the head, and 
with this it pierces the tender root (Fig, 21), in which it ultimately 
embeds itself. The worms continue to grow — in width rather than 
Fig. 21. Tip of cucuml)cr rodt with young nematodes, Hctc- 
rodera radicicola, just entering. Enlarged. 
(Massachusetts Experiment Station.) 
in length — within the root, the female finally l)ec()ming club-shaped, 
but the male resuming its original slender form. The young, hatch- 
ing from the eggs laid within the root, make their way into the soil. 
and thence into new roots. 
Prcventiz'c and Rciucdial Measures. — Tools which have been 
used in soil infested by eel-worms should be thoroly washed or, 
better, sterilized before using ihem in other soil. 
Among the most suggestive methods of treating infested green- 
houses is that used by Mr. W. F. Preston, of Dixon, Illinois. 
Having had serious trouble with nematodes on cucumber plants, 
he used the sterilization process about to be described, but. owing 
to the "solid bed," worms in the unsterilized soil below soon rein- 
fested the treated soil. To prevent this, a cement floor was put in 
the lied about ten inches below the top, the wooden sides Ijeing 
retained. The nematodes did not reappear until the following sum- 
mer, when the vines were old and ready to be removed, as was 
also the soil. They then gained entrance between the cement floor 
of the bed and the wooden side-walls. The soil could proba1)h- be 
wholly protected by making the sides as well as the floor of cement, 
sloping the floor from the center towards each side, and leaving 
holes along the sides, near the floor of the bed, for drainage. 
