A technique is described for the recovery of strongyloid infective larvae from a large number of separate small sample units of pasture. The larvae recovered from each sample unit can readily be counted individually. Tests of the technique have shown that it will recover approximately 90% of the larvae present. The efficiency of the technique is independent of the number of larvae present and of the quantity of sediment containing infective larvae which is obtained from washings of pasture samples.

The life-cycle of many strigeoid trematodes contains encysted metacercariae as disseminating and infective stages. The cyst wall may vary in form from a thin bag-like structure loosely covering the metacercaria (as in Posthodiplostonmm) to a thick layer, closely investing the parasite and forming a cyst of fixed outline. The cyst wall enclosing the metacercaria of Cyathocotyle is of this thick, rigid type. Extensive histochemical studies have been carried out on the cyst wall of Posthodiplostonmm (Hunter and Hunter, 1940; Bogitsh, 19G2), but the characteristics of the other types of strigeid cyst wall are as yet undefined.

The indigenous dogs of Malawi form a fairly homogeneous group. The general type is a smooth-haired, medium-sized, terrier dog in many ways not unlike the Basenji of the Belgian Congo. Consequently it may be assumed that the local breed of dog has, generally speaking, had very little contact with exotic breeds and that it is quite possible the parasitic populations which it supports are also truly indigenous. A unique opportunity of exploring this unknown terrain presented itself when, as a result of an outbreak of rabies, it was decided to thin out the unvaccinated dog population as a veterinary control measure.

1. Three hundred and eighty three birds belonging to fifteen species found dead from starvation as a result of a severe cold spell on the island of Skomer, between 2nd and 5th January 19G2, were examined for enteric helminths. The age, sex and weight of each bird was determined whenever possible and on dissection, the species, location and number of helminths was recorded.

2. Seventeen species of helminths were found, providing sixteen new host records and five new British records.

3. In general, changes in the mean number of helminth species and specimens per bird and per infested bird is directly correlated with changes in the percentage incidence of infestation.

Microfilariae were demonstrated in stained blood films from two New Guinea frogs, Cornufer papuensis, and this material was later given to me by a colleague. The frogs, which had been preserved in alcohol for some months, were examined for adult forms after having been softened in a solution of equal parts of glycerol and 70%alcohol. One male, one female and the anterior part of a second female of a new species of the genus Icosiella Seurat, 1917 were found in one frog. Two females and four males of a new species of the genus Ochoterenella Caballero, 1944 were found in the second frog.

Attempts were made to induce increased resistance to caecal worm infections in chickens and turkeys by giving 5-week-old birds embryonated Heterakis eggs. To test for such resistance, the birds were challenged 28 days later by feeding comparable numbers of embryonated eggs. To study the possible influence of any response on the transmission of blackhead, some of the birds received Heterakis eggs from worms grown in birds that had blackhead.

In blackhead-free chickens there was only a slight reduction in the number of worms recoveied from the initial infection as a result of the superimposed second infection. However, there were 37% fewer worms from the second feeding of eggs than were present in the control birds that had had no previous Heterakis infection. In blackhead-free turkeys, the immunized birds had fewer worms from both doses than did the controls. These reductions averaged about 40% in both instances.

Twenty-eight adult specimens of 2 new species, Aphelcnchoides appendurus and A. montanus, were collected from the rhizoids of moss adhering to the bark of pine trees in the Mussoorie Hills, at an altitude of 7,500 feet above sea level, in Uttar Pradesh, India.

The 2 new species, which belong to the “parietinus” group of the genus Aphelenchoides Fischer, 1894, are described and illustrated.

Of the 1,090 hake, Merluccius merluccius (L.), examined for Aporocotyh spinosicanalis, 323 were infected. Only adult flukes were found and these in the heart and bulbus arteriosus only; this habitat specificity and the apparent strict specificity of the fluke to hake are briefly discussed. The occurrence of from 1 to 5 flukes in each infected fish was common but up to as many as 60 were recorded. The incidence of infection is high in hake from shallow water in some areas to the west of Scotland; a particularly high incidence was found in the Minches and Sea of the Hebrides area. The incidence of infection was very low to the southwest of the British Isles and off Hartlepool in the North Sea; only 1 of 82 fish from these regions was infected. The possible use of A. spinosicanalis as a biological tag is discussed. A significant difference was found in the incidence of infection in hake of different length groups, the most heavily infected being those measuring 26 to 55.9cm.; small hake (25.9 cm. and below in length) from shallow water showed a low incidence of infection. Speculations are made on the possible course of the life-cycle of A. spinosicanalis. There was no significant difference in the distribution of the fluke in male and female fish and no obvious effect on the condition of the host was observed.