100 
Kuhn) attacks a great variety of plants including straw- 
berries, onions, beans and peas, hyacinths, and also feld 
crops. It is an extremely slender species, about 1-25th 
of an inch long, and the males and females closely 
resemble one another. Strawberries when attacked decay 
away at the level of the soil or just below it, and the 
crowns and roots rot away. A remedy is to pull up and 
burn the affected plants and dress the soil with either 
lime or sulphate of potash in the proportion of 1 cwt. to 
the acre. The KNoT RooT EELWORM (Heterodera radici- 
cola, Greef) differs from the previous species in the male, 
being thread-like, while the female is greatly swollen 
except at the head end. It also goes through a more com- 
plex life-history. This species renders its presence evident 
by forming knot-like swellings or galls upon the roots of 
the affected plants. It is a great enemy of cucumbers and 
tomatoes grown in glass houses, but also attacks vines, 
potatoes, lettuces, and many other plants in the open. 
As a temporary measure to save a growing crop, one 
part of permanganate of potash to 200 of water applied 
at intervals of ten days is recommended in the Kew 
Bulletin. \t does not harm the plants, but since it does 
not destroy the eggs of Eelworms, no permanent value 
can be ascribed to it. Treatment of the soil with one part 
of carbolic acid to twenty of water, with a dressing of 
sulphate of potash, 3 cwt. per acre, intimately mixing the 
soil with gas lime or naphthaline, are among the remedies 
that are recommended. When applying remedial measures 
the soil must remain unused for at least six weeks for any 
permanent benefit to be derived. This species, however, 
is extremely difficult to eradicate owing to the fact it 
produces vast numbers of eggs throughout the year, and 
the young Eelworms are thus constantly being liberated 
into the soil. Furthermore, most of the above methods are 
not lasting in their effects, owing to the fact that fre- 
quently a number of eggs remain over undestroyed, and 
serve to start the infection afresh. When a glass house 
is infested with Eelworms, it is often necessary where 
possible, to remove the soil bodily and treat it by one 
of the methods already mentioned. In the case of plants 
grown under glass the horticulturist soon finds that the 
conditions encourage a host of other living things. In 
addition to Eelworms, Woodlice, insects of various kinds, 
and fungi often enforce their presence, and under the 
