Previous experiments on the application of ferric oxide or of calcium cyanamide to “potato-sick” land were carried out at the Kirton Agricultural Institute. The results were reported by Hurst & Franklin (1937), and indicated that ferric oxide had no effect either on the yield of potatoes or on the hatching of H. schachtii larvae, but that calcium cyanamide showed promise and was worthy of further trial. Experiments with this chemical were, by the kind permission of Mr. J. C. Wallace, Principal of the Kirton Agricultural Institute, and with the co-operation of Mr. J. Wood, A.R.C.S., continued for a second year.

During the microscopical examination of the debris collected by flotation from soil infected with the potato eelwormHeterodera schachtii Schmidt, the presence of small numbers of cysts unlike those typical of the potato strain has frequently been observed. The distinguishing characters of these cysts are their dark colour and their lemon-like shape. Similar cysts were seen by chance during observations on “clean” soil which was being used as a control to pot experiments with eelworm-infected soil. This “clean” soil had been obtained from a heap of top-spit material which had been removed from a field on Winches Farm known to have been under grass for at least twenty years, and probably longer.

There have been no previous records of nematode invasion of native grasses in Australia, although “Cockle” in wheat, caused by Anguillulina tritici, and root galls on wheat, due to A. radicicola are known to occur. Mr. J. E. Harrison, Senior Agrostologist, Department of Agriculture, Victoria, found Microlaena stipoides infected as herein described at Lorne in April, 1935. This seems to be the first record of the disease, but it has since been ascertained that it is widely distributed in Victoria.

Preliminary investigations on the problem of affording protection to the potato plant growing in soil infested with cysts of Heterodera schachtii, were carried out by Hurst & Triffitt (1935, i, ii, 1937). In these experiments promising results were obtained by the application of calcium cyanamide or of ferric oxide to the soil, and trials with these chemicals were designed on a larger'scale. A small field experiment (Hurst & Franklin, 1937) was carried out in Lincolnshire during 1936, using dressings of 30 cwt. per acre of calcium cyanamide and 12 cwt. per acre of ferric oxide. On the cyanamide plots an increased yield of potatoes was accompanied by a relatively small increase in the cyst population of the soil. With ferric oxide the results were not significantly different from those on the untreated control plots.

The object of this short paper is to record a number of new host species for certain common helminths of birds. These new records show that the host range of some helminths is not so circumscribed as had been previously believed. Most of these parasites have been obtained at routine post-mortem examinations and hence were the result of natural infections in the field. A few however were the result of experimental feedings at this Institute.

In 1928 Taylor put forward the theory that “…Syngamus trachea is a species within which there may be found a number of strains showing a peculiar physiological adaptation to the host in which they occur.” He had not had much success in a number of experiments in which he had tried to infect chickens with S. trachea from starlings. The first experimental feedings resulted in only light infections though control experiments with the chicken “strain” resulted in much heavier ones. After the first passage through the chicken however, the gapeworms had become more adapted to the new host, and could produce much more serious infections in the next generation.

During the past year about 50 domestic hens from a farm at Wheathampstead, Herts, have been sent to this laboratory for postmortem examination. The birds came in singly at first. Later as the helminthic fauna seemed likely to prove interesting, they were kindly sent in groups of three. When a diseased bird died, a thin one and an apparently healthy one were slaughtered so as to effect a control. The hens had been bought as adults from a number of local farmers and were kept outside on free range. They belonged to the breeds Ancona, Light Sussex, Rhode Island Red or were a cross between R.I.R. and Light Sussex. All the birds seemed to be equally affected.

A field experiment was commenced in Bedfordshire during 1937, when soil infested with cysts of Heterodera schachtii was treated with very heavy dressings of calcium cyanamide. For comparison, a treatment with ammonium sulphate and lime was included. The lay-out was in the form of four randomised blocks of five treatments: control, calcium cyanamide 40, 60 and 80 c.p.a., and ammonium sulphate 80 c.p.a. plus hydrated lime 63 c.p.a. The last dressing contained the same amounts of nitrogen and lime as 80 c.p.a. of calcium cyanamide.