It was determined to examine whether rats injected with non-viable oncospheres of Asian Taenia or Taenia saginata became resistant to challenge infection with eggs of Taenia taeniaeformis, since (a) metacestodes of Asian Taenia and T. taeniaeformis develop in the liver of pigs and rats, respectively, and (b) Asian Taenia and T. saginata have human origins. Rats injected intravenously or subcutaneously with complete Freund's adjuvant with non-viable oncospheres of Asian Taenia showed statistically significant resistance to challenge infection with eggs of T. taeniaeformis, whereas those injected with non-viable oncospheres of T. saginata did not show any resistance.

A complete investigation of the variations likely to occur in the lengths of larvae of Heterodera rostochiensis (for example) under all conditions would involve measuring larvae from a great number of varieties of potato grown in a great number of different localities, and also of larvae from tomatoes of different varieties grown under various conditions. The results obtained so far for this species of Heterodera make but a small contribution towards the mass of information which might be accumulated. Until such further data become available, certain conclusions have been drawn as to the best method of taking samples of larvae for measurement, but it must be remembered that these conclusions may need revision at a later date in the light of new information. According to our present knowledge it appears that the variety of potato on which a cyst has developed does not significantly affect the mean length of the larvae within, but that the mean length of the larvae from a single plant, irrespective of the variety, may differ significantly from that of larvae from another plant. It is also deduced that the variations in the mean lengths of the larvae from different cysts are greater than the variations within the individual cysts. From these facts it follows that if one wishes to estimate parameters for larval lengths of a population of H. rostochiensis larvae, a better estimate will be obtained if one takes a small number of larvae from each of a large number of cysts rather than the same total number of larvae from a small number of cysts. Similarly the cysts should have come from a large rather than a small number of plants, but apparently it is not necessary that the plants should be of as many varieties as possible, though this last assumption is based on information derived from only seven varieties of potato, all of them maincrop varieties, and it may need modification when larvae from other varieties have been examined.

Forty years ago Schøyen (1885) gave an account of a serious disease of barley occurring in the vicinity of Lorn in Norway, which was associated with the formation of galls on the roots of the plants. The galls were found to contain eelworms which had without doubt caused their production and the symptoms of disease also. Schøyen named the worm Tylenchus hordei n.sp. Similar galls had been found at about the same time by Eriksson (1885) on diseased barley at Pajala in northern Sweden, but he had ascribed their formation to the nematode Heterodera radicicola; Schøyen discussed this and gave reasons for thinking it an erroneous view. Closely similar galls had been found previously on the roots of Sea Lyme Grass, Elymus arenarius, by Warming (1877) in Sjaelland, Denmark, and by Trail (1881) at Aberdeen, Scotland. The former had considered that they were caused by Heterodera radicicola, whilst the latter thought they were due to a nematode belonging to the genus Tylenchus, though he was not positive on this as he only saw female worms.

Egg excretion of S. mattheei was studied for about a year from man, baboons and cattle living in their normal environment. Although the excretory pattern was not unequivocal from man, there was a tendency of egg counts to decline with time: the baboons showed a seasonal pattern and the cattle a stable pattern throughout the year.

Beef measles is prevalent in many parts of the world. The two most important factors which allow the dissemination of the disease are, firstly, the insanitary methods of the disposal of human excreta, and secondly, the habit of eating beef raw or almost raw. To eradicate beef measles and Taenia saginata from a country where the inhabitants are eaters of raw beef, would be a costly and difficult undertaking. The fact that Taenia saginata infestation of man is a comparatively trivial disease and, therefore, does not induce many infested persons to seek treatment, is another difficulty in preventing its dissemination. Of 90 cases that came to our notice, 65 did so in reply to an offer of £5 reward for a complete tapeworm (1), and, although the average duration of infestation of these cases was 13 years, many had never previously sought treatment. We consider there are two main methods of preventing bovine cysticercosis. The first is to immunize the cattle against the disease, and the second is to prevent cattle from having access to Taenia saginata eggs. With regard to the second method, if means are undertaken to prevent Taenia saginaia ova from gaining access to a pasture previously contaminated with them, the problem still remains of getting rid of the ova which are already present. This paper considers the latter problem, and is specially applicable to farms irrigated with human sewage. It has been suggested that pastures may be ridded of Taenia saginata eggs by grazing sheep.

The karyotypes of Vampirolepis nana, Hymenolepis diminuta and Vampirolepis erinacei (Cestoda: Cyclophyllidea) have been described. The number of chromosomes in the diploid cell of the studied taxa was 2n = 12. The absolute and the relative lengths of the chromosomes of V. nana and H. diminuta were measured. The chromosomes had similar metric values. In the karyotypes of V. nana and H. diminuta there were ten one-arm chromosomes and.one two-arm chromosome (the third in length in the karyotype of V. nana and the first in length in the karyotype of H. diminuta). The chromosomes in the karyotype of V. erinacei had one arm which was proved by the terminal localization of the constitutive heterochromatin. The examined species differed in the morphology of some chromosomes in the karyotypes.

Aulonocephalus pennula is a heteroxenous nematode that commonly infects a declining game bird, the northern bobwhite quail (Colinus virginianus). There is a lack of information on the life cycle of A. pennula and the potential effects of infection on bobwhites. In order to better understand the life cycle of this parasite, various species from the order Orthoptera were collected from a field site in Mitchell County, Texas. Using polymerase chain reaction (PCR), nine potential intermediate hosts were identified from the 35 orthopteran species collected. Later, ten live specimens were collected to identify larvae within the potential intermediate hosts. Larvae were present in three of these and were sent for sequencing. Similarly, the presence of larvae was confirmed from extra tissues of samples identified as positive with PCR. This was the first study to document potential intermediate hosts, but future studies are needed to confirm that these species are capable of transmitting infection to bobwhite. However, this study demonstrates that PCR has increased sensitivity and may be a valuable tool when determining intermediate hosts.

Observations were made on the biology of Cotylophoron cotylophum in respect of the hatching of miracidia, infection of the intermediary mollusc, emergence and encystment of cercariae, and on the pathogenicity of the parasite. It was noted that miracidia of this parasite hatch in 15 days at a temperature of 28-30°C. At a lower or higher temperature than this hatching is delayed. When the miracidia are mature a sudden fall in temperature hastens their hatching. Darkness has no adverse effect on hatching. These miracidia show a marked attraction towards Indoplanorbis exustus, which are proven to be the intermediary molluscs of this amphistome. At room temperature, ranging between 21-24°C. during the day and 18-21°C. at night, sporocysts develop within the snails in about 24 hours and on the 4th day rediae are seen developing inside the sporocysts.

In a survey carried out in 1991–1992 in the town of Yirka in Northern Israel, 49 dogs were examined for Echinococcus granulosus infection and abattoir data, based on organs condemned for the presence of parasites, was collected. The presence of E. granulosus by arecoline test was demonstrated in 7 (14.2%) of the dogs examined, but no parasites were found in the intestines of five stray dogs shot in the area. A survey of sheep slaughtered in the local abattoir during a one-month period revealed Echinococcus cysts in 10% of the 255 animals examined. No Echinococcus parasites were detected in 21 dogs examined 3 months after the initiation of praziquantel treatment. Echinococcosis seems to be a very serious public health problem in Israel and a control programme needs to be given a high priority.

Magnacercous cercariae with heavily pigmented tails and possessing a pair of eyespots and seven pairs of penetration glands, some of which are para vesicular, were found to develop in the prosobranch gastropod, Cerithium coralium collected from a brackish water locality at Bheemunipatnam, A. P. India. The cercariae developed into metacercariae of Galactosomum ussuriense in the viscera of the fish Therapon jarbua. Successive stages in the development of metacercaria from the cercaria were followed. Natural infections with metacercariae were found in T. jarbua, Valamugil cunnesius and Megalops cyprinoides. The definitive host of G. ussuriense in the present area of investigation is still not known. This represents the second account of part of a life-cycle in the genus Galactosomum.

Susceptibility and development of Clinostomum complanatum in the chicken (Gallus gallus domesticus) have been studied. The progenetic metacercariae of C. complanatum developed into ovigerous worms in 3 days in the buccal cavity of the chicken and survived only 6–7 days in this experimental host. The susceptibility is influenced by the age, sex and breed/type of the host. Both percent susceptibility and recovery of the worms decreased with increase in the age of the host. The egg laying chickens were found to be least susceptible to the infection. Mature male chickens were more susceptible than the females. The single comb white Leghorn (SCWL) was found to be susceptible while the local type (LT) and the cross breed (SCWL×LT) were not susceptible to C. complanatum. The possible reasons for these variations have been discussed.

A new genus and new species, Tarantobelus arachnicida, was found in the oral opening of tarantula spiders bred in captivity in Poland. The new species is characterized by having a small body (0.77–0.95 mm long in females and 0.66–0.84 mm in males), cuticle poorly annulated by transverse incisures, lateral field inconspicuous, lips separated with small cuticular flaps topping each lip, stoma panagrolaimoid with gymnostom well developed with robust and refringent rhabdia, pharynx panagrolaimoid with isthmus slightly longer than the basal bulb, intestine with cardiac (anterior) and rectal (posterior) areas with narrower walls. Mature females with intestinal cells including needle crystal packs, excretory pore at isthmus level, female reproductive system panagrolaimoid with post-vulval sac 0.4–0.8 times the length of the corresponding body diameter and having very thick walls, vulva very prominent, female rectum 0.8–1.3 times the length of the anal body diameter, female tail conical with acute tip with phasmids at 58–62% of its length. Male tail conical with long and thin mucro, spicules ventrad bent having rounded manubrium and thick gubernaculum. Description, measurements and illustrations of the new species are provided. Molecular analyses show its relationship with Brevibucca and Cuticonema. On the other hand, Medibulla and its corresponding subfamily Medibullinae, previously in Osstellidae, are transferred to Panagrolaimidae, being Shahnematinae, the junior synonym of Medibullinae. Indocephalobus, recently proposed and located in the family Panagrolaimidae, is considered a junior synonym of Diplogastrellus (Diplogasteromorpha), and its only species, I. zebrae, is considered a junior synonym of D. gracilis. In addition, a key to identification of panagrolaimoid genera is included.

Since the description by Looss in 1892 of the life-history of Diplodiscus subclavatus, and in 1896 of the miracidia of Gastrothylax gregarius, G. aegyptiacus and Paramphistomum cervi, there have been very few accounts of paramphistome life-histories. Gary (1909) published an account of the life-history of Diplodiscus temperatus, which Cort considered to be incorrect, and Krull and Price (1982) repeated the work on the same species. Beaver (1929) published an account of all the developmental stages of Allassostoma parvum except the sporocyst; Brumpt (1986) described the cercaria and the experimental infection of the intermediate and final hosts of P. cervi in Corsica. Willey (1941) has described the life-history and bionomics of Zygocotyle lunata, but has not given a very detailed account of the development of the egg and miracidium. The fullest account of a paramphistome has been given by Bennett (1986) of a species which was identified as Cotyhphoron cotylophorum, but which Price and Mackintosh (1944) consider to be a new species of the genus Paramphistomum, namely P. microbothrioides. Since the submission of this paper as part of a thesis for the Ph.D. degree, two further papers on the development of paramphistomes have come to the notice of the author. These are by Sinha (1950) on the development of C. cotylophorum in India, and by Willey and Godman (1951) on that of Z. lunata in America.

Four little-known ascaridoid species occurring in crocodilians are discussed. Typhlophorus lamellaris Linstow, 1906 and Hartwichia rousseloti Chabaud& Bain, 1966 are considered to be closely related to Heterocheilus tunicatus Diesing, 1839; Porrocaecum assymmetricum Ortlepp, 1932 is transferred to Trispiculascaris together with T. trispiculascaris Skrjabin, 1916. These three genera are placed in the subfamily Heterocheilinae sensu Sprent (1980) on account of the structure of the oesophago-intestinal junction, the labial pulp and, where known, the male tail. A key to eight genera of Heterocheilinae in crocodilians is provided.

Alveolar echinococcosis (AE) is endemic to Hokkaido, Japan. For the past 20 years, detection of AE among inhabitants has involved serological screening using an enzyme-linked immunosorbent assay (ELISA) followed by Western blotting (WB). Between the years 1987 and 2000, antigens targeted on 66, 55 and 30–35 kDa bands were routinely used in the WB step of AE diagnosis. However, since 2001 diagnosis has been dependent on three smaller molecular weight antigens (26–28, 18 and 7–8 kDa). Due to its higher sensitivity, this improved WB approach has been used as a confirmation step in the screening process and also for the testing of suspected AE cases in hospital outpatients. Using the improved WB technique, a total of 1745 serum samples were examined in 2001–2006 with 81 patients detected and registered with AE. Interestingly, sera from 76 of the 81 diagnosed AE patients (93.8%) demonstrated reactivity with all three antigens. However, sera from the remaining five patients (6.2%) demonstrated no reactivity with the 18 kDa antigen, even though they exhibited clearly detectable levels of reactivity with the 26–28 and 7–8 kDa bands. These results suggest that medical practitioners need to pay particular attention to the specific reactions to some different diagnostic antigens to minimize the risk of misdiagnosing AE patients. In turn, these results may also provide important diagnostic information for cystic echinococcosis (CE).

Six species of digeneans (Proctoeces maculatus (Looss, 1901), Helicometra fasciata (Odhner, 1902), Helicometra pulchella (Odhner, 1902), Macvicaria alacris (Looss, 1901), Peracreadium genu (Nicoll, 1909) and Zoogonus rubellus (Olson, 1868)) were found for the first time in labrid fish (Symphodus tinca (Linnaeus, 1758), Labrus merula (Linnaeus, 1758) and Labrus viridis (Linnaeus, 1758)) from the Bay of Bizerte. Except for P. maculatus and Z. rubellus, which are limited to the rectum, these helminths colonize the entire digestive tract. The study of the seasonal prevalence, abundance and mean intensity shows that three parasites, P. maculatus, H. fasciata and P. genu are present throughout the year while H. pulchella, M. alacris and Z. rubellus are less frequent and appear only in spring (H. pulchella and M. alacris) or in spring and summer (Z. rubellus). The levels of infection and digenean faunal diversity in labrid fish from the Tunisian coasts are generally lower than those from localities within the western Mediterranean.

An early rise in serum IgE levels was observed in five of seven patients with acute primary trichinosis. Parallel increases in the total IgG, IgM and IgA levels, as well as specific IgG and IgM antibody titres to Trichinella spiralis larval antigen, were detected in two. The elevated levels persisted long after the clinical recovery of the patients.

The potential of using 35S-labelled larvae to determine the number of second-stage Toxocara canis larvae present in the tissues of infected animals was assessed. Infective larvae were labelled by in vitro culture with medium containing 35S-methionine. The amount of radiolabel attached to larvae decayed exponentially with time and had an in vitro mean half life of 3·54±0·65 days. The ‘lost’ radiolabel was incorporated into proteins which formed part of the worm's excretory/secretory products. The levels of radioactivity present in different organs of BALB/c mice, infected with 35S-labelled T. canis larvae, varied over the course of infection. Initially most of the radioactivity was present in liver, but over the course of infection 35S liver levels gradually decreased and brain levels increased. By day 14 post-infection the majority of the isotope was present in the brain (p<0·01). Assessment of antibody levels on day 14 post-infection showed that infection with 35S labelled T. canis larvae induced the production of parasite-specific IgM, IgG and IgG1 antibodies.

Responses to parasite antigens were studied in three strains of mice, BALB/c, CBA and NIH, during the initial phases of a primary infection with the intestinal nematode Heligmosomoides polygyrus. Changes in the rate of in vivo cell division were analysed in mesenteric lymph nodes and spleens during the phases of larval maturation and adult establishment, and related to changes in organ size and cellularity. The nature of the proliferating cell populations was also investigated by flow cytometry, carried out on cell suspensions prepared at the time when larval development was complete. The variation in the ability of the strains of mice to become resistant to a challenge infection was manifest as only slight differences in their initial responses to infection. All three strains showed an increase in 125I-iododeoxyuridine incorporation in their mesenteric lymph nodes and spleen, and an increase in B cell frequency over that of T cells in the draining lymph nodes. Although lymph node weight in NIH mice continued to rise over a 4 week period, the majority of responses measured were short lived, peaking 10 to 14 days after infection. The low responder status of CBA mice was thus reflected in a transient and relatively small enlargement of lymphoid tissues, but their early proliferative responses to antigen were similar in scale to those of responder strains.

The infectivity of Apatemon (Australapatemon) minor cercariae to 7 species of freshwater leech was examined under laboratory conditions. The leech species exposed to infection were; Erpobdella octoculata, Helobdella stagnalis, Glossiphonia heteroclita, Glossiphonia complanata, Hemiclepsis marginata, Piscicola geometra, and Theromyzon tessulatum. Five species were capable of acting as second intermediate hosts. Despite this broad specificity only Erpobdella octoculata and Helobdella stagnalis could be considered to show a high degree of compatibility with the parasite. In these 2 leech species more than 38% of the cercariae successfully penetrated and established metacercarial cyst infections. The leeches Piscicola geometra and Theromyzon tessulatum did not become infected. Close parallels were found between the species order of host utilization determined experimentally and that revealed by a range of field surveys in Britain, Eastern Europe and Russia. This suggests that the order of second intermediate host utilization in the natural environment has, at least in part, a physiological basis. The degree to which different leeches are utilized as hosts may relate to the opportunity which they afford for transmission of A. minor to wildfowl definitive hosts.