EELWORMS 553 



saturated three times, at intervals of a fortnight, with a 

 solution of one part of carbolic acid in twenty parts of 

 water. 



2. A second remedy consists in mixing the soil intimately 

 with gas-lime. 



In either case the soil so treated must remain for at least 

 six weeks before it can be used. 



3. When soil in a house is infested, it is safest to remove 

 the whole and treat it outside ; the interior of the house 

 should then be thoroughly washed with a solution of one 

 part of carbolic acid in eight parts of water. 



4. Mixing naphthalene with infested soil has been recom- 

 mended, and some fumigants which contain naphthalene as 

 an important ingredient have been favourably reported on. 



5. A very important and somewhat discouraging fact to 

 bear in mind is that a very large number of plants in addition 

 to the cucumber, marrow, and tomato, have been recorded 

 as host-plants for Heterodera radidcola. Among them are 

 cultivated cruciferous plants, red and crimson clover, black 

 medick, peas and beans, lettuce, potatoes, beet, some grasses, 

 some rosaceous and other fruit plants, and such weeds as 

 the dandelion and the rib-grasses or plantains. The 

 practical import of this on the possibilities of spread of the 

 pest is evident. 



6. In experiments conducted at Kew against another 

 species of eelworm infesting clover it was found that the 

 eelworms were destroyed by treating the diseased plants 

 with sulphate of potash, the quantity used in the experiments 

 being equal to 4 cwts. to the acre. 



The following method of clearing the soil of eelworms is 

 also recommended : 



' Carbolic acid has proved very effectual, and the amount 

 to be used is governed, not by the superficial area but by 

 the cubic content of the soil, which can readily be roughly 

 estimated in the case of a frame. Two ounces of carbolic 

 acid per cubic foot of earth is generally sufficient to eradicate 

 the pest.' 



Journ. Roy. Agric. Soc. Engl^ 68, p. 239 (1907). 







,The Tea eelworm (Heterodera radidcola) is said by Sir 

 George Watt to be very destructive to the tea plant in various 

 parts of India, 75,000 seedlings being killed on one estate 

 alone. It has also been reported from Ceylon. Up to the 



