Thometrema magnifica from Hypostomus commersoni and Loricariichthys anus (new host) is redescribed with additional morphological data and original figures, measurements and figures of Szidat's paratypes. Gibson & Bray's hypothesis that T. portoalegrensis is its synonym is confirmed.

Ultrastructural studies were undertaken on a discrete peri-vulval area of cuticular modification in the parasitic female of Strongyloides cebus. Cilium-like arrangements of microtubules were observed which suggested that this region was sensory in nature. The possible function of this is discussed.

The fish populations of three reservoirs and one river in the Northamptonshire area were examined over a four-year period for the plerocercoid of Ligula iniestinalis. The infection was observed in two of the three reservoirs but was not found in the river Nene. The reservoir which had no infection contained no cyprinids.

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.

5 males and 5 females of this species were collected from the intestine of the giant African rat Cricelomys gambianus from Minaki Secondary School, near Pugu, Tanzania. Some of the specimens have parts of the host's intestinal wall tissues in their buccal capsules and some specimens have the anterior part of the intestine dark in colour. This may suggest that these nematodes attach themselves to their host's intestinal wall and probably feed on its blood.

The elongated body is cylindrical, tapering at both ends, the anterior end recurved dorsally. The cuticle is transversely striated and the buccal aperture is round, lacking a radial crown but the cuticle of the external surface of the buccal capsule forms several annular thickenings around the buccal aperture. There are 4 main external cuticular bands extending to near the buccal aperture. The buccal capsule is funnel-shaped with extremely thick and highly chitinized walls, the dorsal wall notably shorter than the ventral. The thickness of the walls is uneven, with maximum thickness posteriorly. The capsule lacks teeth and the dorsal oesophageal gland terminates near the anterior edge of the buccal capsule. The oesophageal funnel is chitinized. The oesophagus is claviform owith a wider posterior part and ends in a triradiate valve.

The karyotypes of the two amphistomes Calicophoron microbothrium Fischoeder, 1901 and Carmyerius gregarius (Looss, 1896), Stiles & Goldberger, 1910 from Egyptian ruminants were studied using the air drying technique. The two species have similar number of chromosomes (n = 9), but differ in chromosome morphology. All the chromosomes of C. microbothrium are subtelocentric, except the first and the fifth are metacentric, whereas the chromosomes of C. gregarius are submetacentric, subtelocentric and acrocentric. Some cells in the two species showed tetraploidy. The results are discussed in terms of the phylogenetic relationship of different amphistomes.

Cephalobus parasiticus Sandground, 1939, reported from the stomachs of monkeys, is shown to resemble the sour paste eelworm, Turbatrix rediviva, so closely as to be identical with it.

It is suggested that the monkeys probably acquired the nematodes by consuming fruit, or some other vegetable substance, on which the worms were living saprophagously; having been brought to the food by visiting flies.

Regular monthly examination of lungs of donkeys, with a total of 423 in a year, revealed that in Morocco Dictyocaulus arnfieldi infection is present throughout the year with an annual incidence of 47.8% (range 30 to 62.2%). The monthly mean number of worms per animal varied from 19.4 to 69.6 (annual average 39.5) with a maximum of 1000 worms in a donkey. October, February and June are the months when peaks of infections were observed. The ratio of worms in lungs to larvae per g in faeces (L.P.G) ratio varied from 1:0.57 to 1:1.33 (average 1:0.97) and although this relation was significant, cases with high worm burden and no larvae in faeces were observed.

It is well known that the first two larval stages in the life cycle of nematodes belonging to the superfamily Strongloidea, have a freeliving existence. During this time, the larva which hatches from the egg feeds actively, undergoes two moults and grows considerably before reaching the infective stage, when it is ready to invade a definitive host. Under natural conditions this external development takes place in the faeces, which have been deposited by the infected host on ground likely to be contaminated with various bacteria.

The prevalence of guinea worm Dracunculus medinensis was determined in communities in Anambra State, Eastern Nigeria during the 1984–1985 guinea worm season. Thereafter combined intervention measures which included health education and community participation in pond treatment were introduced in one of the two communities. There was a decrease in disease prevalence from 88.7% to 33% in Group A (372 households) and from 88% to 53% in Group B (368 households), two years after control measures were introduced in Igbeagu community. However, in 345 households in Mpu community without control measures, any decrease was not significant (from 88·7% to 86·5%). Health Education combined with pond disinfection proved to be a much better intervention measure, contributing to the change in attitude and therefore decrease in disease prevalence, than pond disinfection alone.

The results obtained in the tests described above are summarized in the following table :—

Matricaria matricarioides (Less.) Porter, self-sown in one of the inoculated pots, is an addition to the known weed hosts of narcissus races of D. dipsaci and a new host record for the species.

Seinhorst (1952) has emphasized the need for caution in interpreting the results of host tests with D. dipsaci. Exposure to heavy infestations will often result in invasion and local necrosis of the tissues of plants which are not true hosts of the race concerned. Seedlings may easily be killed outright in this way. The present tests lead to similar conclusions as shown, for example, by the results obtained with red clover and oat seedlings. Even deposition of eggs in the tissues cannot be taken as evidence that the eelworms have established themselves. It is considered, however, that a plant may be regarded as a true host when it is clear that the eelworms are breeding freely in the tissues, i.e. when eelworms in all stages of development are present with numerous eggs, and when infestation is able to persist during the normal life of the plant. With bulbous plants, the establishment of an infestation in the new bulbs after the leaves and flowers had died down was taken as evidence that the plant was a true host. The typical effects of D. dipsaci on the tissues of its hosts, e.g. hypertrophy of parenchyma tissues, enlargement and loosening of the cells and dry, mealy rotting, are also useful criteria, but some of these effects may be produced occasionally after invasion of non-hosts, as was found in a few of the inoculated clover seedlings.

The finding of tares or common vetch, Vida sativa L., attacked by the stem eelworm, Ditylenchus dipsaci (Kiihn) Filipjev, reported in the foregoing paper by Staniland and Southcy and the correspondence on the subject which passed between Staniland and Goodey, brought to light an interesting point in regard to the accuracy of the first record of the parasite on this particular host which calls for some comment and elucidation.

Neodiplostomum (Conodiplostomum) ramachandrani sp. n. is described from Rattus muelleri in Kepong, Selangor, Malaysia. It is characterised by having symmetrical dumbell-shaped testes, and vitellaria as a single ventral band in the hindbody. The taxonomic relations ofNeodiplostomum, Conodiplostomum and Fibricola are discussed and possible significance of the fluke as an ecological indicator noted.

It was shown that maintenance of cercariae of S. mansoni and S. haematobium at low (10°C) and high temperatures (40°C) markedly increased their mortality during penetration of mammalian host skin. These increased losses in the skin accounted for the known decrease in infectivity, as measured by adult worm recovery, of cercariae kept at low or high temperatures.

Small galls on the leaves of Yarrow or Milfoil, Achillea Millefolium L., were first mentioned by Thomas (1873) but were investigated and described by Löw (1874) who made a new species of the causal organism under the name of Tylenchus millefolii. He dealt with the appearance, size and distribution of the galls, their presence on plants from spring to autumn and the ability of the parasite to revive from galls which had been kept dry from May to October. He described the general structure of the adult worms, gave particulars of their size and proportions, and, in addition to a sketch of a galled leaf, gave a drawing of the adult female and three views of the male tail.

A further modification of a lung perfusion technique was evaluated by examining the recovery rate of 14-day-old Dictyocaulus viviparus worms from the excised lungs of 15 dead bovine calves. Up to 89% of the total number of worms found in 12 l of perfused fluid was recovered in the first 4 l collected. The application of this observation will increase the efficiency of the routine laboratory diagnosis of D. viviparus infection.

Daubaylia elegans n.sp., is described from Planorbis carinatus in the Netherlands. Tables are given of the comparative measurements of the other members of the genus. The main differences between D. elegans n.sp., and these other species are the ratio length to breadth, the length of the tail, the presence of a cuticular knob on the tail of the female and the relative size of the male genital armature.

The influence of nonspecific immunomodulation on the course of experimental infection was examined in larval cestodosis (Mesocestoides corti) and ascaridosis (Ascaris suum) in mice. Immunosuppressive treatment (with azathioprine or hydrocortisone) resulted in a decrease of resistance in both models. The subsequent administration of T-activin to immunosuppressed mice led to the restoration of resistance to a level equal to that of untreated control mice. The administration of different immunomodulators partially protected mice against M. corti (T-activin. thymomodulin) or A. suum (T-activin. thymomodulin. thymosin fr.5. bursa-activin) infection. The protective effect of different treatments did not correlate with the level of specific antibody in the sera of infected mice. These results, which confirmed the decisive role of T-cell immunity in the resistance to the helminth infections, raise the possibility of the use of immunomodulators (thymic preparations) in the immunoprophylaxis of helminthoses.