We have previously described a rat mAb directed against a peptide derived from the vif protein of HIV-1 that recognized two Schistosoma mansoni (Sm) antigens with a major band at 65 kDa. Epitope mapping of this mAb using overlapping hexapeptides derived from the vif peptide revealed that the motif recognized was PLPSVT. The screening of a Sm cDNA library led to the identification of two clones, Sm70 and Sm65. The two deduced protein sequences did not share any common structural features apart from the epitope recognized by the mAb (see below), and did not show significant identity to sequences present in the data bases. However, the N terminus of the deduced sequence of the Sm70 protein exhibits a consensus sequence known to be an ATP/GTP binding site. Furthermore, the C terminus of the deduced Sm65 protein sequence was found to contain a conserved hexapeptide with a consensus sequence LPETGE reported to be an important motif of the surface proteins of gram-positive cocci. Both proteins exhibit a peptide sequence (PLRSVT for Sm70 and PVGSVT for Sm65) similar to the epitope recognized by the mAb anti-vif. Western blotting experiments showed that the mAb anti-vif reacted with both proteins. However, only Sm65 was recognized by sera from HIV-1- seropositive individuals, whereas both proteins were recognized by S. mansoni-infected patients.

It has been determined that anaplasmosis may be transmitted by Dernmcentor andersoni under the following conditions: (1) Larvae may acquire the infection by engorging on a bovine whose blood contains anaplasms and may transmit the infection as nymphs to susceptible bovines; and (2) in a similar manner the nymphs may acquire the infection and transmit it as adults. The test of “hereditary” transmission was negative, i.e. the larvae did not apparently acquire the infection from adult females which engorged on carriers of anaplasmosis. Conditions of transmission by D. andersoni are the same as those which have thus far been determined by me for D. variabilis. The incrimination of these two species of tick points to the possibility that anaplasmosis occurring anywhere within the known range of distribution of that disease in the United States may be tick-borne so far as a coincident distribution of known tick carriers can establish this possibility.

The new species herein described, collected by Mr Charles Elton in the course of ecological field work in Norway, was very kindly passed on by him to me for identification and description.

A colony of the ixodid tick Hyalomma (Hyalommina) kumari was bred in the laboratory and all stages described. The known hosts and distribution of the tick in India are given briefly.

While making a survey of the parasites of littoral fishes at Cullercoats, Northumberland, parasites from Mola mola and Raniceps raninus came into my possession. These fishes are rarely found in British waters and so far no parasites have been recorded from R. raninus in British waters.

Two new species of Giardia are described: G. wenyoni sp.nov., from the duodenum of slender loris, Loris tardigradus lydekkerianus, and G. dasi sp.nov. from the duodenum of palm-civet, Paradoxurus hermaphroditus hermaphroditus.

The distinguishing features of G. wenyoni are (measurements in microns): range of length 12·0–20·0, average 15·6; range of breadth 5·5–11·5, average 8·8; ratio of length to breadth 1·7; distance from anterior end to centre of nucleus 4·5; centre of nucleus to ends of lateral shields 7·0; ends of lateral shields to posterior end 3·6; breadth across centre of nucleus 7·7; length of the sucker 6·2; the ratio of body length to the length of sucker 2·5. The nuclei do not lie parallel to the axostyles. Each nucleus contains chromatin granules along the periphery.

G. dasi is distinguished by its dimensions which are (in microns): range of length 11·8–20·0, average 15·5; range of breadth 5·0–12·5, average 7·2; ratio of length to breadth 2·1; distance from anterior end to centre of nucleus 4·7; centre of nucleus to ends of lateral shields 6·0; ends of lateral shields to posterior end 5·4; breadth across the centre of nucleus 6·6; length of the sucker 6·0; the ratio of body length to length of sucker 2·5. Chromatin granules are present in the form of a ring in the centre of the nucleus. The most characteristic feature of this organism is the presence of certain large granules in the cytoplasm.

Between January 1961 and March 1962 the writer made a parasite survey of twenty-three Wilson's Snipe, collected in Northern Colorado. Eleven birds were found to be infected with a previously undescribed species of hymenolepid cestode. The following description of a new species is based upon twenty-seven complete specimens recovered from the small intestines and caeca of these snipe.

The two specimens of trematodes herein described were obtained from the intestine of an Indian Ruff, Philomachus pugnax. Of six birds examined, three harboured a few of both species. The genera to which these worms belong have not been hitherto recorded from India.

Females of Littorina obesa, L. scabra and L. littorea have been shown by other workers to grow more rapidly than the males so that they predominate in the larger size groups. They are significantly more numerous than the males among the larger specimens of L. neritoides on the Plymouth Breakwater.

More male than female snails are infected by a larval trematode, Metacercaria A, when it occurs alone, and the percentage infection falls when the proportion of males falls. A second larval trematode, Cercaria B, infects more female snails than males. Infections with this species alone remain consistently low, but where it occurs in the same snails as Metacercaria A the percentage infection rises rapidly, that is, in the larger size groups of the snails where the females predominate. Females infected by Cercaria B appear then to be attractive to the metacercariae.

Evidence is given to show that it is extremely unlikely that these large female snails were originally males in which sex reversal has occurred.

This different intensity of infection of the sexes of L. neritoides is considered to be primarily responsible for the shapes of the curves when infection is plotted against size, and it does not appear likely that primary infections with larval trematodes cause acceleration of the growth rate in this species.

It is thought that ecological factors on the breakwater are likely to be the chief causes of the large size attained there by L. neritoides.

Parasite burden (by volume) was measured in female mice of three strains given single or concurrent infections of Mesocestoides corti and Taenia crassiceps. Significant suppression of T. crassiceps volume was observed over a range of M. corti inocula and occurred irrespective of whether M. corti was introduced before or after infection with T. crassiceps. Suppression of T. crassiceps volume was greatest with larger inocula of M. corti and with increased duration of M. corti infection. No significant difference was found in the intraperitoneal volume of M. corti from mice given single or simultaneous concurrent infections of M. corti and T. crassiceps. When M. corti were inoculated into mice with an established infection of T. crassiceps a significantly smaller volume of M. corti was retrieved at post-mortem from the peritoneal cavities of these mice, than from mice given just M. corti.

Female sex pheromone reception was inhibited in a bioassay by treating males of the beet cyst nematode, Heterodera schachtii, with the sulphydryl reagent, mersalyl acid. This effect was blocked by the sulphydryl group protectant, dithiothreitol, indicating the occurrence of sulphydryl groups in the receptor molecules and a role for sulphydryl groups in pheromone reception.

Antigens were extracted from the epicuticle/cuticle of intact female Onchocerca volvulus using 2% 2-β-mercaptoethanol and 1% SDS. In Western blot analysis a human infection serum selected for its high antibody titre against whole worm homogenates did not recognize any component solubilized by 1% SDS. However, the same serum did bind at least 7 antigens among the material extracted with 2-β-mercaptoethanol. These antigens have apparent molecular weights (Mr) of: 15 000, 18 000, 28 000, 78 000, 98 000, 120 000 and 200 000. In ELISA using this preparation as target antigen, 151 out of 153 human infection sera gave positive results. An Onchocerca-specific IgG1 monoclonal antibody, designated Cam1, recognized the 28 000 Mr antigen, which is the most prominent antigen detected by Western blot analysis using human infection sera. In ELISA, using material affinity-purified with Cam1 as target antigen, 149 out of 153 human infection sera gave a positive IgG response. From a cDNA library three expressing clones were isolated with a rabbit serum raised against 2-β-mercaptoethanol solubilized material. One of these clones was recognized by the monoclonal antibody Cam1.

1. Three new species of dermanyssid mites of the subfamily Entonyssinae are described. These are: Entonyssus heterodontos n.sp. from Heterodon contortrix contortrix, Ophiopneumicola elaphes n.sp. from Elaphe obsolete, obsoleta, Ophiopneumicola natricis n.sp. from Natrix sipedon pictiventris.

2. Keys for the identification of male and female mites of the Entonyssinae are given.

3. 141 snakes, representing thirty-five species, were examined for lung mites. Thirteen individuals, representing eight species, were found to be infested.

4. Two species incertae sedis, one from Pituophis sayi, the other from Coluber constrictor flaviventris, are discussed.

5. Problems of classification and distribution of this group of parasites are discussed.

1. P. tularensis may be abundant in the midgut lumen, the epithelial cells of the anterior third of the midgut, and the haemolymph of the louse. Multiplication is extracellular in the lumen and the haemolymph and intracytoplasmic in the gut cells.

2. The multiplication of the tularemia organisms in the midgut epithelium eventually leads to the disruption of these cells and the break-through of the organisms into the body cavity. The growth of these organisms in the haemocoele results in the death of the louse in 4–7 days.

3. Lice vary greatly in their susceptibility to infection. Some lice show complete resistance to infection; others are capable of retaining the infection essentially for their normal life span, i.e. 35 days; still others apparently succumb to a rapid increase of the organisms in a relatively brief time after infection.

4. The behaviour of P. tularensis within the louse presents interesting similarities to infection of lice with the rickettsiae pathogenic to humans.

The capacity of Acanthocheilonema viteae to metabolize fructose was investigated in vitro. In common with other filarial species A. viteae oxidized fructose to lactate but its rate of consumption was only 40% of the glucose-containing control value. Fructose was not incorporated into glycogen. Release of 14CO2 from [U-14C]fructose was not detected in the presence of glucose and was about 40% of the glucose-containing value under conditions where fructose was the sole hexose substrate. Fructose consumption and lactate excretion increased in proportion to the external concentration of fructose. However, worm viability was not maintained in fructose over a 120 h in vitro incubation. In the presence of fructose, protein synthesis (measured incorporation of [35S]methionine into acid-insoluble material) was reduced compared to the glucose-containing control group; but was significantly greater than the value obtained under glucose-free conditions.

This interesting and peculiar parasite was apparently first noted and studied by George Newport in 1831. That writer, however, was unable to publish his observations till 1849, by which date he had been anticipated in authorship by Francis Walker for the specific name, and by J. O. Westwood for the generic. With the latter Newport engaged in a somewhat protracted controversy touching priority of name, morphology, habits, etc., of Melittobia. There can be no doubt that Westwood's genus, very briefly characterised in Proc. Ent. Soc. Lond. for 5th July, 1847, p. xviii, must stand. The part of the proceedings containing this page was published on 12th January, 1848. As the purpose of the present notes is chiefly to offer a more accurate description of M. acasta, and as, besides, I am at present engaged in revising the whole genus, it does not seem necessary to say much on the habits of the insect. M. acasta is markedly polyphagous; never apparently a true hyperparasite, it attacks everything within its limited range of action. Already it has been bred from a long list of hosts, and somewhat contradictory conclusions about the insect's parasitic status and economic value may be drawn from its host attachment. Thus it may be a pest in nests of bees, wasps, etc.; a species of Melittobia again proved a serious menace in the laboratory to Tachinids introduced into the U.S.A. to combat the Gipsy Moth, but possibly, the insect plays, or may be induced to play, a useful part in destroying dipterous puparia in or near houses, or in surroundings where the adult may skulk secure. For Melittobia dislikes light, and the ♀ flies little, though when once established in a suitable environment, it is hard to dislodge.

ON 19. v. 1934, while trawling from S.S. Salpa, kindly placed at my disposal by the Marine Biological Association, Plymouth, the following Lernaeidae were taken:

Twenty-three years ago, the first and only report of synergism between malarial and coccidial infections in chickens was published. In view of the potential commercial importance of this possible parasitic interaction in some parts of the world, and the lack of further supporting publications, this disease complex has now been reconsidered. An experiment on Plasmodium gallinaceum and Eimeria acervulina revealed no interaction of any kind between these species and a re-examination, with statistical analysis, of the raw data on which the original publication was based shows that no evidence of synergism between malarial and coccidial infections in chickens has so far been produced.

That parasitic worms may induce bacterial invasion from the intestine has frequently been asserted in explanation of the sporadic occurrence of some bacterial and virus diseases of animals. Weinberg, in 1907, gave an extensive review of the literature dealing with inflammatory conditions of the intestine, due to bacterial invasion associated with parasitic worms. He also gave an account of some original clinical observations. He concluded that, by biting and boring into the intestinal wall, or by wounding it with hooks and suckers, the majority of helminths favour the penetration of microbes, these being carried on the exterior and in the intestine of the worms. In one case, where a fatal septicaemia was associated with the presence of a single individual Trichocephalus, the author's conclusion, that even isolated worms are very dangerous, appears to be rather strained. Records of clinical observations of this kind frequently appear in the literature, but, as a general rule, the evidence showing the agency of the worm is very slender and amounts to little more than the observation of the presence of worms in animals suffering from some bacterial disease.

As a major morphological feature in establishing the form of the nervous system, it is recognized that neurons are initially overproduced, then naturally occurring cell death reduces the neuron number to the functional requirement. However, the mechanisms controlling the selective elimination of certain neurons during a general phase of cell death are not fully understood. One event that seems to be pivotal is the establishment of neural connections, the degree of which may be influential regarding the fate of specific neurons. However, little quantitative evidence is available to either support or refute this theory. In this current study, a Stereological measurement of gap junction per neuron was carried out within the invertebrate model system of the tapeworm metacestode Mesocestoides corti, which has previously been shown to overproduce neurons during the asexual reproduction stage of its life-cycle. Novel Stereological estimation methods with ‘ vertical sections’ indicated that prior to asexual division the cerebral ganglion possessed approximately 268 neurons, each with a gap junction surface area of 250 μm2. As division progressed, the neuron number increased to approximately 700, while the total surface area of gap junction remained statistically unchanged. As a result the surface area of gap junction per neuron decreased to 106 μm2, less than half that in the undividing stage. These results provide the first non-biased quantitative data regarding changes in the mean surface area of gap junction per neuron in a developing cerebral ganglion.