1. Laboratory experiments have shown that solutions of ferric chloride, ferrous sulphate and chinosol, in sufficient concentration, have a lethal action on the larvae of H. schachtii. The vapours given off by potassium ethyl xanthate were also found to be lethal.

2. Each of these four chemicals was mixed with moist infected soil and the mixture left for a period. When the cysts were separated and placed in a solution of potato-root excretion, the numbers of larvae which hatched were reduced as a result of the chemical treatments, in the order: potassium ethyl xanthate, ferric chloride, chinosol, ferrous sulphate.

3. When ferric oxide was placed in a solution of root excretion containing cysts, the commencement of hatching was delayed.

4. Experiments on a very small field scale were carried out, the chemicals being applied chiefly to the rows in which potatoes were planted. The plants growing on the treated areas did not, in general, show marked symptoms of root-eelworm infection as did those on the control areas.

5. The yields of potatoes from each row are tabulated. The highest yields were obtained following the treatment with ferric oxide.

During the course of experimental work on the factors governing the escape of larvae from the cysts of Heterodera schachtii, a preliminary series of experiments was carried out to determine whether the admixture of artificial fertilisers with infected soil modified in any way the rate of hatching of the larvae. It was thought possible, firstly, that some form of fertiliser might have a lethal effect on the cyst contents or on the larvae during their passage through the soil before they succeeded in entering the roots of the host; secondly, that the fertiliser or its break-down products in soil might neutralise or retard the action of potato-root excretion, which normally stimulates the larvae to escape from the cysts and attracts them towards the roots of the plant; or thirdly, that the larvae might be stimulated to hatch to some extent even in the absence of the host-plant.

It is a recognised fact that the potato-strain of the eelworm Heterodera schachtii is distributed from district to district by the agency of cysts embedded in soil adherent to seed tubers. The need for some method of freeing seed tubers from viable eelworm, and the extent to which infection may be carried by seed grown in eelworm infested land, are strikingly illustrated by observations carried out by the staff of the Ormskirk Potato Testing Station, which, by permission of the Director of the National Institute of Agricultural Botany, are quoted here.

Mr. L. Ogilvie, Mycologist, of the Research Station, Long Ashton, Bristol, recently sent the writer some bulbs of Lilium longiflorum Thunb., var. takesima, requesting an opinion on the eelworms occurring in the brownish tips of some of the scales. These turned out to be chiefly a species of Rhabditis and Diplogaster nudicapitatus Steiner. There was one thoroughly decomposed bulb scale, dark brown in colour and of a soft consistency throughout which, on teasing in water, was found to contain several insect larvae, mites and numerous nematodes including specimens of Diplogaster longicauda and D. striatus. In addition, about 25 adults of each sex of a new genus of nematode were found which, though somewhat resembling Rhabditis in buccal and oesophageal characters, differed from that genus in certain important features the most outstanding of which was the short buccal cavity. On this character the generic name has been based and because the worms were found in a thoroughly decayed organic medium a specific name has been chosen which denotes their probable feeding habits. Mr. Ogilvie has informed the writer that the bulbs were from stocks imported from Japan. Such bulbs arrive in this country in cases packed with Japanese soil but as the bulbs examined had already been planted in English soil it is impossible to determine from the material available whether the newly discovered nematodes were originally inhabitants of Japanese or English soil.