It was observed in laboratory experiments that the lethal action of dilute solutions of calcium cyanamide on the larvae of Heterodera schachtii was more rapid when these solutions were rendered slightly acid. This might be due to the rate of decomposition of calcium cyanamide in aqueous solutions of varying þH. The changes which cyanamide undergoes in acid and alkaline media have been described by Crowther & Richardson (1932). Solutions of commercial calcium cyanamide are moderately alkaline because of their lime content, and in this alkalinity any free cyanamide which is formed tends to polymerise to dicyanodiamide. Experiments with solutions of dicyanodiamide showed that this substance has very little toxic action on H. schachtii larvae. In acid solution, on the other hand, cyanamide is hydrolysed to urea. This substance becomes toxic when it decomposes to ammonia, but in the slightly acid solutions used the change would be a slow process. It is probable, therefore, that the degree of toxicity of calcium cyanamide solutions would be greatest where the cyanamide radicle could be retained unchanged for the longest period.

One of the peculiarities of the eelworm Heterodera schachtii which makes it a very difficult parasite to control is the length of time it can survive in a dormant condition in the soil. In this state the embryonated eggs are protected by the resistant cyst wall, and, in the case of the potato strain of the eelworm, the larvae only hatch in large numbers in the presence of the host plant. On account of this property, land infected with the parasite remains infected even though the host plant is not grown. It is however well known that if “potato sick” land is rested from potatoes for a few years it is then sometimes possible to grow a potato crop giving a fairly good yield and showing little or no sign of sickness in the overground parts. In these cases, however, it is often found that the roots of the plants are heavily infested with eelworm. These and other observations have led to suggestions that other factors may be associated with H. schachtii in giving rise to the condition known as “potato-sickness.” Such factors may be due wholly or in part to soil conditions, climate, fungal attack or the time of attack by the eelworm. In some cases more than one factor may operate in addition to the nematode, and in different cases it is probable that different factors come into play.

The helminthic fauna of a number of Water Deer, Hydropoles inermis from Whipsnade Park has been examined.

Fourteen species of Nematodes were recovered, all of which were new records for this host.

Ostertagia lyrata and O. grühneri are recorded for the first time in England.

Trichostrongylus cervarius n. sp is described.

The differential blood count of the normal laboratory rat shows at all times a greater proportion of lymphocytes than of neutrophiles. In rats infected with 400–600 larvae there is within 2–4 days of the infection a great relative, and possibly absolute, neutrophilia with a corresponding lymphocytopenia, which becomes less marked as the infection progresses, though the percentage of neutrophiles remains above, and that of lymphocytes below, the normal average. This neutrophilia is accompanied by a moderate left shift in the Cooke polynuclear count which may persist for a considerable period. At the same time the infection is immediately followed by a relative eosinopenia or aneosinophilia which persists for 1–5 days and is probably due to the setting up of a local eosinophilia in the sub-mucosa of the intestine. Thereafter the eosinophilia becomes generalised and reaches its maximum in 7–16 days after infection, with considerable fluctuations from day to day, finally settling to a low-grade eosinophilia which may persist for some months. The degree of eosinophilia appears to be only generally related to the severity of the infection and depends on the individual host animal. Persistence of aneosinophilia is an unfavourable prognostic sign.

Small galls on the leaves of Yarrow or Milfoil, Achillea Millefolium L., were first mentioned by Thomas (1873) but were investigated and described by Löw (1874) who made a new species of the causal organism under the name of Tylenchus millefolii. He dealt with the appearance, size and distribution of the galls, their presence on plants from spring to autumn and the ability of the parasite to revive from galls which had been kept dry from May to October. He described the general structure of the adult worms, gave particulars of their size and proportions, and, in addition to a sketch of a galled leaf, gave a drawing of the adult female and three views of the male tail.

Hexatylus viviparus, a spear-bearing nematode superficially resembling Aiiguillulina dipsaci, was originally described by the writer (1926) from a diseased potato tuber. In a second note published the same year (1926a), further details of its structure were given; the organisms in this case being obtained from a gladiolus corm affected with an internal soft rot.

Since the appearance of these papers the writer has encountered this species on several occasions both in potato tubers and gladiolus corms. The receipt of a gladiolus corm in February, 1937, the brown rotten centre of which contained numerous specimens of the worm, provided further material for detailed observations on the structure of the worms. Some of the decayed central tissues of the corm also served as an inoculum for the cultivation of the nematode, along with a fungus, on slope cultures of a malt extract agar. Subcultures from the original slopes have been made from time to time and on these the worms have been successfully maintained for more than twelve months.

A skin infection called by the local Malays “ sawah itch ” has been known in Negri Sembilan, Federated Malay States, for some years, where it has been recorded from widely distributed areas in this State and also from the rice-fields adjoining the Tampin-Malacca road. It is essentially associated with padi-cultivation and is especially prevalent during those periods when the soil is being ploughed or “ chankolled ” prior to planting with rice seedlings, which occupation necessitates workers spending hours each day with their legs submerged in the mud and water of the sawah. (Sawah = swamp or tract of ground covered with water.) I am indebted to Dr. J. W. Field of the Institute for Medical Research, F.M.S., for permission to quote the following extract from his unpublished report on “ sawah itch.”