Bildungsanomalien verschiedener Art kommen bei Cestoden relativ häung vor. Wiederholt wurden dreikantige Taenien mit Y-förmigem Querschnitt und einem Scolex mit 6 Saugnäpfen beschrieben, Zwischenschaltung unvollständiger keilförmiger Glieder, gefensterte Proglottiden, gegabelte Gliederketten und Umkehrung oder Verdopplung des Genitalapparates. Eine weitere Missbildung besteht darin, dass Glieder miteinander verschmolzen sind, so dass auf mehr oder weniger langer Strecke Gliedergrenzen zwischen den aufeinanderfolgenden Genitalsätzen fehlen. Diese Anomalie wurde von Colin (1875) als “Taenia fusa” oder “T. continua” bezeichnet. In den meisten veröffentlichten Fällen dieser Art war das Fehlen der Segmentation auf einzelne Stücke eines sonst normal gegliederten Wurmkörpers beschränkt. Hierher gehören z.B. folgende bei Taenia-Arten des Menschen beobachtete Fälle: ein Sammlungs-exemplar von 1830 des Royal College of Surgeons in London, das Blanchard (1894) beschrieb und abbildete, die Fälle von Colin (1875), Vallin (1877), Welch (zit. n. Blanchard 1889), Bork (1891) und eine Eigenbeobachtung von Blanchard (1894). Auch bei dem Hundebandwurm Taenia pisiformis sind entsprechende Miss-bildungen von Teilen der Strobila beschrieben worden (Neumann, 1896, Roudabush, 1941).

1. Nematobothrium labeonis n. sp. from the orbit of three species of Labeo is described.

2. The more recent literature relating to the classification of the genus is considered.

3. N. labeonis is contrasted with related species.

In 1923, the writer in studying some species of the family Trichostrongylidæ, had occasion to create a new genus Graphidioides to receive the form previously known as Graphidium affine (Megnin, 1895), Railliet and Henry, 1909. This species differs from the type species of the genus Graphidium on the following points: absence of cervical papillæ, shape of bursa and disposition of ventro-ventral rays, shape of accessory piece and spicules, shape of the ovejectors and vagina and posterior extremity of the female. In an addendum on the remaining species of Graphidium, G. rudicaudatum the following statement was made:—

“Graphidium rudicaudatus R. & H., 1909, from Viscacia viscacia from Argentina resembles G. affinis very closely. It differs mainly by its smaller size, equal ovejectors, sharply pointed externo-dorsal ray and absence of an accessory piece. Its affinities to Graphidioides are so close, that the latter point requires re-investigation. The other points are only of specific value, and it is proposed to include it in this new genus. Should the absence of an accessory piece be confirmed, its position would require re-determination.”

In connection with investigations of the United States Bureau of Fisheries in Alaska in 1906, Professor H. B. Ward spent considerable time in the study of the parasites of the Pacific salmon. Around Excursion Inlet he secured a large amount of valuable material. The following study was made of one of the specimens collected by him, to whom I am grateful for the loan of it.

In 1988, 1989 and 1990 second year grazing heifers, naturally infected with gastrointestinal nematodes, were separated into two groups, one of which was treated orally with albendazole. In 1988 and 1989 treatment was administered immediately after parturition (February), and in 1990 during the last term of pregnancy (December). Both treated and control animals were grazed on separate plots in a rotational system. Maximum faecal egg counts were observed amund parturition, except in 1990, when treatment was given at the end of gestation. The main genera identified were Cooperia, Trichostrongylus, Ostertagia and Oesophagostomum. The number of Ostertagia larvae in the treated groups increased from 1989 to 1990, while the others decreased. Pasture contamination with third stage larvae (L3) was lower on the piots grazed by treated heifers. Maximum numbers of L3 were found in autumn, at the end of winter, and at the beginning of spring. Mean serum pepsinogen concentrations were significantly higher in the untreated groups. This concurs with the pattern for L3 on pasture. The trial shows that if a single treatment against gastrointestinal nematodes is carried out, and the animals remain on contaminated pastures, the parasitic load tends to level out after 4–5 months under favourable climatic conditions. However, the percentages of nematode genera occurring in the new populations may differ from those in the original infection.

The relationship between the cercarial allergen and two previously isolated egg allergens (J1, J2) of Schistosoma japonicum was examined especially in terms of the cross-reactivity between them. Semi-purified cercarial allergen (JAC) was obtained from the crude extract of S. japonicum cercariae by gel chromatography on Sephadex G-200. The apparent molecular weight of JAC was estimated approximately as 60–100 kDa. JAC could bind to Con A-Sepharose, indicating its glycoprotein nature. Three groups of BALB/c mice were immunized with JAC, J1 or J2 using A1(OH)3 as adjuvant, and the cross-reactivity of each antiserum was examined by PCA. Anti-JAC, anti-Jl or anti-J2 serum was highly specific to the corresponding antigen. When IgE-ELISA of S. japonicum patient sera was performed using JAC, J1 or J2 as an antigen, the correlation between anti-J1 and anti-J2 (r = 0.78) was high, whereas the correlation between anti-JAC and anti-J1 (r = 0.27) or between anti-JAC and anti-J2 (r = 0.12) was low. These results suggest that most IgE epitopes on cercarial allergen are independent from those on egg allergens in S. japonicum.

The worm burden in grazing ewes was studied. Analysis of the results showed that correcting worm egg counts (e.p.g. fresh faeces) for variations in faecal D.M. content and in total faeces output is not of any great benefit unless precise information is available.

Data are also presented which suggest that under normal circumstances variations in the sub-clinical worm burden of adult grazing ewes are not related to any variations in food intake.

Compressed organ autoradiography has been utilized to study the migration of the homogonic strain of Strongyloides ratti from the site of skin penetration to the gut. This transit is characterized by rapid disappearance of parasites from the cutaneous site of infection, followed by vascular dispersal throughout all organs investigated. For the first time, parasite migration in both naive and previously sensitized hosts is compared; the principal stations of migration are the same in the two groups although there is a quantitative difference in accumulation of parasites with time in these stations. Parasite attrition occurs in both groups of animals; however, in naive rats it is not manifest until day 20–25 post challenge, whereas in sensitized rats immune elimination occurs as early as 48 h post challenge.

Three new records are made, viz: Achillurbainia recondita Travassos, 1942; Metadelphis evandroi Travassos, 1944; Rhopalias coronatus (Rudolphi, 1819) Stiles and Hassall, 1898; all are recorded from the manicou, Didelphis marsupialis insularis (Allen) from Trinidad, British West Indies. Descriptions of all these species are given.

Strongylus (Dicerocola) tremletti sp.nov. is described from the black rhinoceros, Diceros bicornis L. from Kenya.

The affinities of S. (D.) tremletti sp.nov. with the other species of the genus Strongylus Müller, 1780 are discussed and the subgenus Dicerocola subgen.nov. is erected to contain it.

The species of Strongylus in Kenya are noted and original drawings of S. (D.) asini Boulenger, 1920 are included.

Populations of Pasteuria penetrans isolated from root-knot nematodes (Meloidogyne spp.) and cyst nematodes (Heterodera spp.) were tested for their ability to adhere to a limited selection of sheathed and exsheathed animal parasitic nematodes, free living nematodes, including Caenorhabditis elegans wild type and several srf mutants, and plant parasitic nematodes. The attachment of spores of Pasteuria was restricted and no spores were observed adhering to any of the animal parasitic nematodes either with or without their sheath or to any of the free living nematodes including C. elegans and the srf mutants. All spore attachment was restricted to plant parasitic nematodes; however, spores isolated from cyst nematodes showed the ability to adhere to other genera of plant parasitic nematodes which was not the case with spores isolated from root-knot nematodes. The results are discussed in relationship to cuticular heterogeneity.

Species co-occurrences and interspecific associations between intensity of infection were studied in helminth communities of three populations of brown trout, Salmo trutta, from northern Italy. Of the eight helminth species, only four were common enough to be included in the analyses: Pomphorhynchus laevis, Acanthocephalus anguillae, Echinorhynchus truttae and Cyathocephalus truncatus. The observed frequencies of co-occurrences of the different species, based on presence/absence data, did not differ from those predicted by a null model derived from prevalence data. However, the intensity of infection (number of individuals per fish) of different helminth species were generally, but not always significantly, negatively correlated in tests of pairwise associations. Variation in fish sizes and its effect on infection levels, and whether or not two helminth species used the same or different intermediate hosts, had no influence on these findings. Of the few significant negative associations found between pairs of helminth species, none was found in more than one fish population. This suggests that interspecific associations may be condition-dependent: even in apparently similar localities, the same combinations of helminth species show different associations. Without evidence of replicability, it is almost impossible to conclude to the consistent role of competition between any pair of helminth species in the field.

Of 17 Trichinella isolates from domestic pigs and wild boars (Sus scrofa) in regions where Trichinella nativa is widespread among sylvatic animals, two wild boars from Estonia were found to be naturally infected with this Trichinella species. The other 15 animals were infected with Trichinella spiralis. Trichinella nativa is tolerant to freezing when in the muscles of carnivores. The biological characteristics and temperature tolerance of this species in swine need to be further investigated if pork is certified for consumption following freezing.

The prevalence of Spirocerca lupi in 260 privately owned dogs with different life and hunting styles in Greece was based on the examination of randomly taken faecal samples using Teleman's sedimentation technique. The dogs did not demonstrate any clinical signs of spirocerciasis. Although the prevalence was 10%, it was found to be significantly higher in trace hunting dogs (21%), than in scent hunting dogs (5%) and household pets (0%). There was no relationship between prevalence and age/sex of dogs. The impact of life and hunting styles on the prevalence of S. lupi in the dog and that of the faecal examination technique, are discussed.

Five fish species used for preparation of a popular dish (cebiche) made with raw fish flesh in Mexico were obtained from five localities of the coast of Yucatan. Lutjanus synagris, Gerres cinereus, Sphyraena barracuda, Epinephelus morio and Haemulon plumieriwere examined for the presence of larvae of anisakid nematodes, causative agents of human anisakiasis. The nematode Pseudoterranova sp. was found in E. morio and S. barracuda with a total prevalence of 83% and 6.5 ± 6.2 worms per fish for E. morio, and a prevalence of 33% and 10.2 ± 30.0 worms per fish forS. barracuda. Contracaecumsp. was found to infect G. cinereus with a prevalence of 57% and 7.6 ± 11.4 worms per fish. The relatively high prevalence of Pseudoterranova sp. indicates that this parasite is a potential causal agent of anisakiasis on the coast of Yucatan. Although all larvae were found only in the mesentery of the fish host, their importance as a potential source of human infection cannot be excluded as larval migration to the muscles in dead fish is possible.