This description of a new species of Paraspidodera is based on material from the Helminthological collection of the London School of Hygiene and Tropical Medicine which was handed to the writer for examination by Professor R. T. Leiper, F.R.S. The parasite had been collected by Dr. Sells from the wild pig in Uganda; no indication of the habitat is given. The writer wishes to thank Professor Leiper for placing this material at his disposal.

Inorganic elements as micronutricnts play a vital role in metabolism and in immune mechanisms (Ballerker & Prasad, 1983) and a significant role in the physiology of parasites. Their importance is shown by the harmful effects of mineral deficiencies in the host diet, particularly on gastro-intcstinal parasites (Von Brand, 1966). The presence of aluminium, cadmium, iron, manganese, nickel, sodium and tin has been shown in the corpuscles of Echinococcus granulosus which causes hydatid disease in man (Agosin, 1968). In this preliminary report, the quantities of trace elements in hydatid fluid from sheep and man are reported to show their possible importance as nutrients or as cofactors in the metabolism of the parasite.

Analysis of Giemsa-stained mitotic metaphase plates of Microsomacanthus spasskii and M. spiralibursata (Cestoda: Hymenolepididae) revealed the diploid chromosome numbers for both species to be 2n=6. The karyotypes are remarkably similar in general morphology; they both consist of three pairs of metacentric or meta-submetacentric chromosomes graded in size from 4.3 to 7.0 μm. Slight interspecific differences exist in the position of the centromere of chromosomes of the pair 3. Based on existing chromosome data the possible pathways of the karyotypic evolution within the family Hymenolepididae are discussed.

Xenopodistomum xenopodis Macnae, Rock and Makowski, 1973 was recovered from the gall bladder of Xenopus laevis laevis imported from the Cape Peninsula, South Africa, during 1967 – 1978. The overall incidence amongst 396 toads was 2.8%, and while the maximum intensity was 8 worms per host, most carried single infections. The parasite was not represented in 570 specimens of 8 other Xenopus taxa from East, Central and West Africa. The internal anatomy of X. xenopodis is of a plagiorchild type, but the adult body form is unusual with marked division into a slender very extensible neck and a broad oval hindbody. Although apparently confined within the gall bladder, the parasite can extend its neck along the bile duct and into the duodenum: host gut contents or intestinal epithelium may therefore supplement the diet of bile fluid. The original description and generic diagnosis have been amplified and amended. X. xenopodis apparently lacks close affinities with other known genera, a characteristic common to many of the parasites which infect the clawed toads.

The pathomorphological effects of daily and weekly doses of liposomized albendazole on Trichinella spiralis larvae have been examined and compared during the course of muscle infections in mice. Treatment with three and six daily doses of the drug given by intraperitoneal injection to mice resulted in marked pathological alterations to encapsulated larvae, mainly in the walls of the capsules. There was a 5% efficacy against T. spiralis in mice given three daily doses of albendazole, and 38% efficacy in mice given six daily doses of the drug. The same doses of drug, when administered weekly, did not reduce the numbers of parasite larvae, and the application of drug at 6-weekly intervals resulted in a 5% reduction in numbers.

Cercaria pseudocellata Szidat and Wigand, 1934; C. bilharziellae polonicae Szidat, 1929; C. kenilworthensis n.sp. and C. edgwarensis n.sp. are recorded from London. Descriptions of the two new species and a comparison with related forms is given.

889 complete alimentary tracts were examined for helminths during a two-year survey of sheep and goats in Cyprus. Faecal samples were also examined for worm eggs.

The most common parasites found were Ostertagia and Trichostrongylus spp. and a list of all the parasites and their prevalence is given.

Bunostomum trigonoceplialum, Parabronema skrjabini and Skrjabinema ovis were found for the first time in Cyprus.

The infection rate of each of the worms was studied and the results showed that most of the worms followed the same general pattern, having a peak in the spring and another in the autumn, separated by a trough during the hot dry summer period, when the infection rate yvas low. There were variations within this pattern, Trichostrongylus spp. having a spring peak that was more pronounced than the autumn peak. The reverse occurred with Ostertagia, Chabertia and Oesophagostomum spp., which had a more pronounced autumn peak than spring peak and a lower rate of infection in the summer.

Variations in the infection rate were also noted between the two years of study.

The reasons for these variations are discussed and it appears that weather has some influence on the timing and duration of the peaks but that other factors must also be involved. It is suggested that with some species inhibition of development of the immature stages may occur over the hot dry period, and that these immature worms resume their development towards the end of summer.

A similarity was noticed between the seasonal distribution of the different worm species in Cyprus and in the winter rainfall areas of Australia.

This investigation was carried out for two reasons, firstly that there would appear to be no detailed description of the changes in the leaf structure in Plantago lanceolata L. under the influence of parasitization by Anguillulina dipsaci (Kühn) Gerv. & v. Ben., and secondly that material for study was readily available.

As the interesting and complex family the Proteocephalidae is represented by several forms not only from the Sudan but from various parts of the world, a brief summary of it is made below.

Mice infected with Nematospiroides dubius show non-specific immunodeprcssion (NSID) of immune responses to concurrently administered antigens. This project investigated the factors influencing the response of oxazolone (T-dcpcndcnt antigen) and LPS (T-indcpcndent antigen) in infected mice. Depressed responses to both antigens were observed in mice infected with N. dubius, although the pattern of immunodeprcssion was influenced by both the level and the relative timing of infection and antigen presentation. Consistent NSID was only achieved when the mice were given the higher levels of infection and there was some evidence that NSID was more severe when infection preceded the administration of antigen by 14 days.In general, although NSID was significant, the degree of immunodepression was not considerable. It was concluded that the underlying mechanism of NSID was likely to be different from that enabling the parasite to survive in the intestine of the chronically infected host, and that altered physiology and host's modulation of the immune responses in heavily infected animals may have given rise to a general weakening of the immune system. It was suggested that future work should investigate NSID and parasitespecific immunodeprcssion locally in the intestine where parasite survival is likely to be determined by events at the nnicosal surface.

Although lightly homogenized three-week-old Schistosoma mansoni incubated in Mistuhashi and Maramorosch insect tissue culture medium or the medium of Weller and Wheeldon produced adherent cell layers, continued growth of these cells did not occur. Non-adherent cells obtained by trypsinization also failed to produce long term cell cultures even after the addition of a range of growth factors. The possibility of producing tumour-like schistosome cells by the use of the mutagen ethyl methane sulphonate was therefore examined. Four-hour exposure of three-week-old schistosomes caused in some worms (a) large fluid filled ‘ballooning’, which also occurred in adult males, (b) enlargement of the gut, (c) increase in numbers of large round cells within the worms and (d) tissus outgrowths. It is suggested that these effects of mutagen offer new approaches to obtaining permanent schistosome cell cultures.

An eosinophil chemotactic factor (ECF) was partially purified from plerocercoids of Spirometra erinacei by a combination of anion-exchange chromatography on DE52 and gel filtration on Sephacryl S–200. The molecular weight of ECF was estimated to be 25 000–45 000 by high-pressure liquid chromatography. The ECF was bound with concanavalin A-Sepharose. The ECF was sensitive to periodate oxidation and to heating (56°C, 30 min). On isoelectric focusing, eosinophil chemotactic activity was clearly revealed at pI 4·1. These results suggest that ECF of S. erinacei plerocercoid is an acidic glycoprotein. An intradermal injection of ECF induced eosinophil attractions in the normal guinea pig skin.

1. The structure of the head in the families Acuariidae and Habronematidae is described. It is established that the first is characterized by the cephalic papillae being on the pseudo-labia and all the cephalic elaborations being modifications of the pseudolabia and by paired structures arising dorsally and ventrally from the inner surfaces of the pseudo-labia. The second family is characterized by the presence of large, single labia, dorsally and ventrally, which cany the cephalic papillae.

2. The family Acuariidae contains three groups, accepted as subfamilies. Acuariinae: characterized by long cordons produced by the development posteriorly of both the inner pseudo-labial flanges and the edges of the pseudo-labia; Seuratiinae: characterized by a cephalic cap developed largely from the outer surface of the head posterior to the pseudo-labia; Schistorophorinae: characterized by the presence of various lobes or helmet-like modifications derived from the inner surface of the pseudo-labia.

A turkey poult sent for post-mortem examination to the Veterinary Research Division, Ministry of Agriculture, Northern Ireland, was found to be suffering from a very heavy infection of a small fluke.

Leipernema leiperi n.g., n.sp. is described from the pangolin Manis pentadactyla in India. Both parasitic and free-living generations have been examined. Features which differentiate the parasite from Strongyloides and Parastrongyloides are described.

Aulolaimus oxycephalus de Man, 1880 is redescribed with observations on the lectotype male and on specimens from England. The definition of the family Axonolaimidae Sch. Stek. and de Coninck, 1933 is emended to include reflexed ovaries. Aulolaiminae n.subfam. is proposed, within the Axonolaimidae, for the genera Aulolaimus de Man, 1880 and Pseudoaulolaimus Imamura, 1931. A. meyli Loof, 1961 is considered to be a species inquirenda. Pandurinema Timm, 1957, is made a synonym of Aulolaimus and further observations are made on A. filiformis (Timm, 1957) n.comb.

Cercariae develop from individual germinal cells occurring freely within the posterior body cavity of rediae. Individual germinal cells give rise to a germinal ball which becomes enveloped by increasing numbers of cytoplasmic extensions originating from specialized parenchyma-like cells, termed nursc cells. Up to eight cytoplasmic layers of nurse cells invest larger germinal balls. These layers may provide mechanical support for developing embryos and/or play a role in the provision of nutrients to them. The cercarial tegument develops from superficially located somatic cells in the germinal ball. Cytoplasmic extensions of presumptive tegumental cells fuse laterally to form a syncytial layer beneath the encapsulating nurse cell layers. As the cercarial tegument differentiates further, the cytoplasm of the nurse cell layers becomes vacuolated and ultimately these layers degenerate. The surface tegumental syncytia of intra-redial cercariae and newly released extra-redial cercariae are nucleated. Separate subtegumental perikarya develop with further differentiation of extra-redial cercariae.

By growing potatoes in infested soil in sectional wooden boxes, changes in the population of potato root eelworm have been observed at 5, 9, 13 and 19 weeks after planting, and at 5 two-inch levels in the soil. Results show that most of the increase in population occurred during the last 6 weeks of the experiment and that the normal population changes proceeded more slowly in the topmost level, leading to a lower final population in that level.

Various populations of laboratory bred bulinid snails were exposed to miracidia of Schistosoma bovis from Mbozi. The parasite is naturally transmitted by Bulinus globosus in the area. Laboratory infection revealed a good relationship with B. forskalii and B. globosus from Mbozi and a population of B. forskalii from Dar es Salaam (infection rates 100%, 63·6% and 41·7% respectively). Populations of B. globosus and B. nasutus from Dar es Salaam were refractory. It appears that both snail species (B. globosus and B. forskalii) present in Mbozi district transmit S. bovis.