Haemonchus longistipes specimens were collected from experimentally infected Sudanese goats and camels for morphological studies. The specimens from goats were much smaller than those from camels, but their infectivity to camels was not affected by their passage in goats. Goats inhabiting the same areas as camels in the Sudan were found to be naturally infected with H. longistipes, but sheep were not and were resistant to experimental infection.

Species identification based on the morphometry of opisthaptoral hard parts, in combination with internal transcribed spacer ribosomal DNA (ITS rDNA) region sequences, confirmed the presence of four viviparous Gyrodactylus von Nordman, 1832 (Plathyhelminthes, Monogenea) species on Nototheniid fish from the Prince Gustav Channel (Weddell Sea, Antarctica). Gyrodactylus antarcticus Gusev, 1967 was found mostly on Trematomus newnesi Boulenger (93 specimens) but also on T. bernacchii Boulenger (one specimen), the latter representing a new host record for this species. Gyrodactylus byrdi Hargis & Dillon, 1968 and G. coriicepsi Rokicka, Lumme & Ziętara, 2009 were recorded on their type hosts, T. newnesi and Notothenia coriiceps Richardson, respectively. Gyrodactylus wilkesi Hargis & Dillon, 1968 was found mostly on the fins of T. bernacchii (29 specimens), but also on T. hansoni Boulenger (one specimen) and T. newnesi (three specimens). The finding of G. wilkesi on T. newnesi represents a new host record. The low number of Gyrodactylus specimens may indicate an accidental infection. The occurence of all four Gyrodactylus species in the Prince Gustav Channel represents a new locality record. According to phylogentic methods, the newly redescribed monogeneans belong to the Antarctic lineage, forming a sister group to North American and European marine Gyrodactylus species, and consist of two species groups, one comprising G. coriicepsi and G. nudifronsi Rokicka, Lumme & Ziętara, 2009, and the other G. anarcticus and G. wilkesi.

The parasite fauna of cod (Gadus morhus) is well described, but the life cycles of Baltic cod parasites are known only in general terms. Invertebrates commonly found in the stomach of cod are recognized as intermediate hosts in the life cycles of nematodes or acanthocephalans. The aim of this study was to determine the source of infection of Baltic cod with parasites found in situ in invertebrates present in the cod stomach. Our results indicate that Saduria entomon is both a source of infection of Baltic cod with parasites and an intermediate host in the life cycle of Hysterothylacium aduncum in the Baltic Sea.

Oxyhaemoglobins of six digenetic trematodes,—Srivastavaia indica, Gastrothylax crumenifer, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri, and of their 3 vertebrate hosts, Bubalus, bubalis, Sus scrofa, Wallago attu, were subjected to alkali denaturation at a pH of 12·4. All oxyhaemoglobins from trematodes and their hosts differ from each other in the rate and extent of alkali denaturation which may be explained due to variations in the amino acid sequences of a particular haem protein in addition to other factors.

Adult forms of members of the Callodistomidae always parasitize the gallbladder of freshwater fishes and occur in Africa and America. This study provides a description of a new South American species belonging in Prosthenhystera from the gallbladder of a characid fish (Bryconamericus ikaa), and ribosomal gene sequences (28S rDNA and ITS1-5.8S-ITS2) are used to demonstrate molecular differences between the new species and congeners as well as explore interrelationships among congeners. Additionally, the first cytological analysis is conducted for a member of the family to determine chromosome number and arrangement. Prosthenhystera gattii n. sp. most closely resembles Prosthenhystera caballeroi in morphology, but the vitellarium is more extensive reaching anterior to the caecal bifurcation in the new species and the uterus is confined to the hindbody in P. gattii n. sp., whereas it extends to the level of the pharynx in P. caballeroi. Also, the testes, cirrus sac, seminal receptacle and the ratio of body length to width are larger in P. gattii n. sp. Independent Bayesian inference analyses of 28S rDNA and ITS1-5.8S-ITS2 sequence fragments produced phylograms that showed P. gattii n. sp. is more similar to Prosthenhystera obesa + Prosthenhystera oonastica than P. caballeroi + two unidentified species of Prosthenhystera, but with poor posterior probability support for the node in the ITS1-5.8S-ITS2-based phylogram. Further, the genetic distance between P. oonastica and P. gattii n. sp. are the largest among Prosthenhystera spp. Cytological analysis revealed ten metacentric chromosomes, which is fewer than the 12–18 chromosomes present in species from the closely related Gorgoderidae.

The generation of protective immunity by various stages in the life-cycle of Strongyloides ratti and the phases against which resistance is directed has been examined in murine strongyloidiasis. Mice were exposed to natural, complete infections, were treated with thiabendazole (which largely resembles the natural infection), were treated with cambendazole (which restricts infection to the larval stage), or infected directly by oral transfer of adult worms. Mice that were infected with infective larvae alone did not become resistant to infective larvae or the complete infection but were resistant to adult worms implanted directly into the gut. Mice exposed to adult worms alone were resistant to natural infections and adults worms implanted directly but were not resistant to infective larvae. On the other hand, mice that had received prior natural infections showed evidence of resistance to infective larvae, adult worms, and natural, complete infections. It is concluded that there is immunological cross-reactivity between infective larvae and adult worms but that under certain circumstances the infective larvae are able to evade the host's protective immune response.

In a recent paper the writer (Goodey, 1943) has shown that the stem eelworm, Anguilulina dipsaci, occurred in considerable numbers in the scape, i.e. the flower stem, and the inflorescence of onions grown for seed in Sussex during 1943. The worms, mainly consisting of infective larvae, occurred in the dry papery tissues lining the hollow scape, in the pedicels of the flowers and in various of the floral organs, such as withered sepals and petals, in the receptacle and placenta and on the walls of the seed capsule. They were also attached to the outside of the ripened seed. In a second paper (Goodey, 1945) it is further shown that the parasite becomes firmly attached to the seed chiefly in the region of the hilum, whence it cannot be removed by the usual processes of winnowing and cleaning. The foregoing results were obtained from plant material in a dry condition and seed samples which had been threshed and cleaned. Study of this material had made it evident that the parasite must somehow gain access to the living tissues of the scape and inflorescence as these grow from the parent bulb, but it was not apparent how this came about; whether from lightly infected parent bulbs or direct from the soil. Circumstantial evidence had been adduced in the two papers, already mentioned, pointing to lightly infected parent bulbs being the probable source of infection, but the whole matter needed further investigation to elucidate this and other points. In the present communication the results of studies directed to the solution of these questions are given.

Up to the present time no taeniacidal agent has been established on the basis of adequate evidence as satisfactory for the removal of tapeworms, especially Davainea proglottina, from poultry. Tapeworms are generally regarded as responsible for considerable damage to the poultry industry. The principal remedies that have been recommended are areca nut, turpentine, oil of chenopodium, extract of male fern, Kamala, pomegranate root bark, arecolin hydrobromide and thymol.

Helisoma trivolvis (Pennsylvania strain) snails naturally infected with Echinostoma trivolvis larvae were maintained for 10 months (300 days) at 4°C in artificial spring water to determine the effects of storage on parasite survival. Three of 20 snails were alive at 10 months and when isolated in spring water at 22−24°C released active cercariae. The mean number of cercariae released in 2 h from each stored snail was significantly less than that from freshly collected snails. Infectivity of cercariae from stored hosts to experimentally infected, laboratory-raised Helisoma trivolvis (Colorado strain) snails was significantly less than that of cercariae from fresh hosts based on cyst recoveries in the Colorado strain of H. trivolvis within 24 h p.i. There was no significant difference in the redial number or the number of cercariae per redia in stored versus fresh snails. In conclusion, some reduction in cercarial emergence and decrease in cercarial infectivity to a second intermediate snail host occurred following storage of H. trivolvis naturally infected with E. trivolvis in ASW at 4°C for 10 months.

In each month for one year 30 perch. Perca fluriutilis L., 1758. were examined for infection with Acanthocephalus lucii (Müller. 1776): 7·78°, of the population was infected with a mean intensity of 2·61 worms/infected fish. No seasonality of occurrcncc of maturation was observed owing to limited data. In older fish the incidence and intensity of infection was greater than in younger specimens. The parasite was significantly over-dispersed within the perch population, k = 00395...P(x2 = 9·07)>0·05. All specimens of A. lucii were found in the third quarter of the intestine from the pyloric caeca to the rectum. Evidence is presented in favour of mutual exclusion between A. lucii and the cestode Proteocephalus percae (Müller, 1780) and the nematode, Camallanus lacustris (Zoega, 1776).

Observations made by various workers over many years have indicated more or less clearly the probability that there is in this country a race of the stem eelworm, Anguillulina dipsaci, capable of attacking oats, field beans, onions, rhubarb, parsnips and certain common weeds. One of the earliest records bearing on this is that provided by Bos (1892) who cited information, supplied to him by Miss Ormerod, which showed that field beans might be seriously attacked by the parasite when grown after oats which had suffered from “tulip-root”. Many years later Johnson (1936a & 1940) reported failure of beans from eelworm attack following “tulip-root” oats in fields in Yorkshire and showed the significance of common chickweed and cleavers as reservoir hosts on which the parasite can live in the absence of susceptible farm crops. In another paper (1936) he showed that A, dipsaci associated with crown-root of rhubarb is interchangeable between rhubarb and oats in both of which it is capable of setting up disease symptoms. In his 1940 paper this investigator showed that A. dipsaci from rhubarb readily infests oats and common chickweed and also transfers to beans and, further, that the parasite from both oats and beans is infective to cleavers and common chickweed and back from both these weeds to oats and beans.

Nematodes identified as Spirura rytipleurites seurati are described and illustrated by light and scanning electron microscopy from specimens collected from the stomach of hedgehogs (Erinaceus europaeus) in Sicily. They differ from S. auriti, a stomach parasite of Hemiechinus auritus, in the length of body, the position of the second pair of post-cloacal papillae in the male and the structure of the spicules. The nematodes are classified as S. rytipleurites seurati, a stomach parasite of Erinaceus algirus, but they differ slightly from it in the dimensions of the eggs, that we measured in the uterus, and in the shape of the amphids. This appears to be the first report of S. rytipleurites seurati from Italy and from E. europaeus.

The nature of complement binding to the surface to infective larvae of Trichinella spiralis and Nippostronaylus brasiliensis differs. When worms were incubated in serum from uninfected hosts, washed and incubated in fluorescent reagent the whole surface of T. spiralis fluoresced but in N. Brasiliensis fluorescence was confined to the anterior end and some internal organs. The outer structure of the cuticle of the T. spiralis larvae was shown not to contain ATP-ase, thus differing from many cell membranes.

In this study two new species are added to the only known species in the genus Serticeps.

Serticeps buckleyi sp. nov. was found under the horny layer of the gizzard of the Eastern Beautiful Sunbird, Neclarinia pulchella incidipectus from Uganda. Serticeps osmanhilli sp. nov. was also found under the horny layer, from a Yellow-winged Sugar Bird, Cyanerpes cyaneus from Brazil.

The genus Serticeps is amended.

The genera Galactosomum, Microlistrum and Stictodora are compared, and, while the first two are undoubtedly synonymous, the last is considered to be distinct.

The adult of the type-species of Galactosomum, G. lacteum, is fully described for the first time from European cormorants, and G. phalacrocoracis is regarded as a synonym.

A new species, Galactosomum fregatae, is described from the frigate-bird Fregata magnificens rothschildi.

The characters of all the species that have been assigned to Galactosomum are briefly defined, and a provisional differential key is given.

Since 1935 a large number of chemicals including chloro-acetic acid and various water-soluble chloro-acetates, received from the Pest Control Committee of Imperial Chemical Industries, have been tested for their value in controlling the potato strain of Heterodera schachtii under the direction of Prof. R. T. Leiper, F.R.S.

Soils from Yorkshire and Ayrshire were used in the experiments, as they are of very different types, and might conceivably respond differently to chemical treatment.

The activities of some key enzymes of the glycolytic and pentose phosphate pathways were investigated histochemically in adult female Onchocerca fasciata (Nematoda: Filarioidea). The distribution patterns of phosphofructokinase (PFK), aldolase (ALD), glyceraldehyde 3-phosphate dehydrogenase (G3PDH) and glucose 6-phosphate dehydrogenase (G6PDH) in different tissues of the worm were determined by employing NitroBlue Tetrazolium (NBT). The glycolytic enzymes PFK, ALD, and G3PDH were distributed throughout the hypodermal tissue, somatic muscles and reproductive organs. These enzyme activities were predominantly expressed in the hypodermal and reproductive tissues, both of which appeared to be metabolically more active than adjacent tissues. The high activities of the enzymes studied in the hypodermal tissue when compared with the minimal or low activity in the intestinal epithelium support the assumption that the worm's intestine, in contrast to the body wall, plays no significant role in the nutrient acquisition process. The results emphasize that both the glycolytic and hexose monophosphate pathways of carbohydrate metabolism are active components in energy production and biosynthetic processes in the various tissues of the worm. The functional significance of these glucose-metabolizing enzymes has been discussed with regard to their location in the tissues concerned.

The material on which this paper is based was received by Prof. R. T. Leiper from several sources, and includes specimens collected in British Guiana by the Filariasis Commission, in West Africa by Dr. Yale Massey, and in New Guinea by Dr. G. M. Heydon. In addition there was a tube received from Dr. O'Connor from Samoa labelled on the outside of the bottle “Pig, Samoa, Ank. Duod. from intestine,” and inside (presumably by Dr. Clayton Lane) “Crassisoma samoense.” It contained specimens of the latter species only. The type material of Lane's two new species from the pig was also available for examination.

A retrospective study on different Lymnaea glabra samples collected from central France between 1993 and 2010 was carried out to determine the prevalence of natural co-infections with Calicophoron daubneyi and Fasciola hepatica, and to specify the composition of redial burdens. Experimental infections of L. glabra performed during the same period of time were also analysed to study metacercarial production of each digenean in co-infected snails. Controls were naturally or experimentally co-infected Galba truncatula. In natural co-infections, prevalence was 0.7% in L. glabra (186/25,128) and 0.4% in G. truncatula (137/31,345). Low redial burdens were found in these snails, with F. hepatica rediae significantly more numerous in L. glabra than in G. truncatula (7.5 per snail instead of 5.2). In contrast, the total numbers of C. daubneyi rediae in both lymnaeids were close to each other (4.3 and 3.0 rediae, respectively). In experimentally co-infected groups, prevalence was greater in G. truncatula than in the other lymnaeid (6.3% instead of 3.0%). Significantly shorter patent periods and lower metacercarial production for each digenean were noted in L. glabra than in G. truncatula. However, in both lymnaeids, the two types of cercariae were released during the same shedding waves and several peaks during the patent period were synchronous. In spite of a greater shell height for L. glabra, metacercarial production of both digeneans in co-infected snails was lower than that in G. truncatula, thus indicating a still incomplete adaptation between these French L. glabra and both parasites.