Four specimens of this trematode were obtained from the small intestine of Kachuga smithii in December 1929. Two of the specimens were not sexually mature; for thought they possessed well-developed testes, ovary and a very small receptaculum seminis, they lacked the uterus and ova. In one of these immature specimens the vitellarian follicles were very feebly developed.

Through the kindness of Mr Nelson Annandale, Director of the Indian Museum, I have recently had the opportunity of examining a small collection of Pentastomids from that Museum. The collection contains one new species of Porocephalus and affords examples of new hosts and new localities in which species already known have been found. In all there were four different species.

The following case of Intestinal Myiasis occurred in a boy about twelve years of age, in normal health, who brought to me in September 1909 what he took to be “worms” discharged with his faeces. He said he did not feel anything abnormal but saw a mass of the creatures upon and in his freshly-voided faeces. He called his mother, and she stated to me afterwards that the “worms were in a cluster like a swarm of bees,” they were crawling about the faecal mass which was loose in character, as had been the case for several days. They varied considerably in size, as did the specimens brought to me. The mass of creatures would have filled one or two tablespoons.

Apicomplexan parasites cause devastating diseases in humans and livestock. Previously we demonstrated that antibodies targeting transmissible forms of the apicomplexan parasite, Eimeria, are effective at reducing parasite shedding thus preventing the transmission of the disease. However, the mechanisms responsible have not been fully defined. Moreover, there is no direct evidence that the parasite-specific IgG antibodies can reach the parasite developing in the enterocytes of the infected chicken host. This study summarizes our efforts using host immunity, parasite proteomics and 3D microscopy to provide a step forward in our understanding of how this immune response works. Eimeria maxima is an important pathogen of poultry and used as a surrogate for a number of human pathogens including Toxoplasma and Plasmodium. Our studies demonstrate that immunization with the purified wall forming bodies (WFBs) results in a production of parasite-specific IgG antibodies, which have the ability to reach in situ gametocytes in the intestinal lumen and permeate the enterocyte/parasite membranes in order to bind to the cytoplasmic Type 1 and Type 2 WFBs. This raises the intriguing possibility that via this process antibodies block the development of Eimeria maxima in vivo.

Cell extracts of an entero-invasive protozoon of squirrel monkeys, Tritrichomonas mobilensis, contained relatively high proteolytic activity, measured on hide powder azure (HPA). Multiple proteinase forms, optimally active at pH 5–7, were detected by electrophoretic analysis in gelatin-containing polyacrylamide gels. Three major proteinase bands of apparent low molecular weights, Mr 18, 23 and 30 kDa, were seen on gels. Inhibition-activation studies suggest that only cysteine proteinases were involved in HPAase and gelatinolytic activities of T. mobilensis cell extracts.

The isolation and molecular characterization of the gene coding for L14 ribosomal protein from L. braziliensis is described. There are 2 copies of the gene per haploid genome, repeated in a head-to-tail tandem orientation and located in a single chromosome of approximately 950 kb. Northern blot analyses indicate the presence of a single transcript of 0·95 kb which is up-regulated when parasites reach the stationary growth phase. L. braziliensis L14 gene codes for a 175 amino acid long polypeptide showing 75–83% sequence identity with L14 proteins from trypanosomatids and approximately 25% with its counterparts from higher eukaryotic organisms. L14 ribosomal proteins from trypanosomatids and higher eukaryotes share along their molecules a similar distribution pattern of theoretically functional domains. L. braziliensis L14 recombinant protein is not recognized by sera from cutaneous leishmaniasis patients. Immunization of mice with one dose of L14 recombinant protein and a second dose of L14 protein covalently linked to the HSP70 from Trypanosoma cruzi induces a high antibody level against this L14 protein, which is mostly of the IgG2a subtype, as well as a strong increase in splenocyte proliferation index.

The lateral diffusion (DL) properties of the fluorescent lipid probe 5-N (octadecanoyl) aminofluorescein (AF18) inserted into the surface of muscle-stage larvae of Trichinella spiralis were investigated by fluorescence recovery after photobleaching. AF18 was not free to diffuse laterally in dormant larvae, and this remained unchanged after larval activation in vitro with trypsin and bile. However, a significant increase in surface fluidity of the probe was demonstrated (%R = 74·5; DL = 11·5 × 10−9 cm2/sec) when larvae invaded intestinal epithelial tissue following oral infection of mice. Membrane-permeant photoactivatable caged cyclic AMP was used to analyse the putative mechanism responsible for this increase in lateral diffusion in the parasite surface. Although incubation of larvae with 1–50 μM caged cAMP had no effect on surface fluidity, incubation with 100 μM caged cAMP induced a substantial increase in the lateral mobility of AF18 (%R = 64·3; DL = 8·3 × 10−11 cm2/sec) immediately following photo-activation of the caged messenger. This induced fluidity, however, was transient and the larval surface reverted to immobility within 15 min. These observations constitute the first reported measurement of the fluid properties of the surface of intracellular parasites, the first demonstration of the parasite surface fluidity altering as a result of host cell invasion and the first indication of a mechanism underlying changes in surface fluidity in parasitic helminths.

The parthenogenetic metacercarial stages of the gymnophallid trematode Cercaria margaritensis are found in the extrapallial cavity of the subtidal prosobranch mollusc Margarites helicinus. The primary metacercariae (M1) produce second-generation metacercariae (M2) which become independent and give rise to M3 metacercariae which are infective to the definitive host, the common eider (Somateria mollissima). This study used transmission electron microscopy to follow the development of M2 inside M1 organisms and M3 inside M2 organisms. The process is similar in both cases with embryos developing from individual cells from the parent body walls. In each case the brood sac was divided into brood chambers by multilaminated cells and both M2 and M3 embryos developed inside embryonic membranes that originated from specialized blastomeres. The tegument of M2 and M3 embryos developed in a similar manner underneath the embryonic membrane. Both the multilaminated cells and the embryonic membranes possessed features that indicated that they are involved in transport of nutrients. It is suggested that the continuous nature of M2 and M3 embryo development may well be similar to that postulated for ancestral digeneans.

Aragão (1912) has recently described a new species of tick which he raised through three complete generations upon cold-blooded animals, the natural hosts in Brazil. He gave the species the name Amblyomma agamum because reproduction occurred parthenogenetically, males not having as yet been observed. The tick, in common with most other Ixodidae, feeds upon three successive hosts in the larval, nymphal and adult stages; it may, however, undergo metamorphosis from larva to nymph upon the host. This observation of Aragão's is the first of the kind, for parthenogenesis has not hitherto been observed in ticks. In the course of his raising experiments he obtained thousands of females which laid fertile eggs in the absence of males.

Immunoactivation depends upon the antigen potential to modulate T-cell repertoires. The present study has enumerated the effect of 61 kDa recombinant Leishmania donovani co-factor-independent phosphoglycerate mutase (rLd-iPGAM) on mononuclear cells of healthy and treated visceral leishmaniasis subjects as well as on THP-1 cell line. rLd-iPGAM stimulation induced higher expression of interleukin-1β (IL-1β) in the phagocytic cell, its receptor and CD69 on T-cell subsets. These cellular activations resulted in upregulation of host-protective cytokines IL-2, IL-12, IL-17, tumour necrosis factor-α and interferon-γ, and downregulation of IL-4, IL-10 and tumour growth factor-β. This immune polarization was also evidenced by upregulation of nuclear factor-κ light-chain enhancer of activated B cells p50 and regulated expression of suppressor of mother against decapentaplegic protein-4. rLd-iPGAM stimulation also promoted lymphocyte proliferation and boosted the leishmaniacidal activity of macrophages by upregulating reactive oxygen species. It also induced 1·8-fold higher release of nitric oxide (NO) by promoting the transcription of inducible nitric oxide synthase gene. Besides, in silico analysis suggested the presence of major histocompatibility complex class I and II restricted epitopes, which can proficiently trigger CD8+ and CD4+ cells, respectively. This study reports rLd-iPGAM as an effective immunoprophylactic agent, which can be used in future vaccine design.

It was found that antelopes in the Serengeti area, Tanzania, East Africa, are heavily infested with lung nematodes. Five species of the family Protostrongylidae, namely, Protostrongylus africanus sp.nov., P. etoshai Ortlepp, P. gazellae Yeh, Pneumostrongylus calcaratus Mönnig and P. cornigerus Ortlepp, as well as one species of the family Dictyocaulidae, Dictycaulus viviparus (Bloch), were recorded.

A detailed description of Protostrongylus africanus sp.nov., which is conspicuous for its gigantic size, is given, and the lesions caused by this lung nematode are described.

The distribution and incidence of lung nematodes in the various antelope species are discussed.

The biochemical constitution of the copepod parasite Mytilicola intestinalis was determined and seasonal changes were detected which, in general, could be correlated with the life-history of the parasite.

Biochemical constituents have been discussed in relation to those in other endoparasites and free-living crustaceans. It was concluded that carbohydrates and lipids both formed important stores of energy in M. intestinalis. Protein levels were reduced compared with those in free-living forms.

This work forms part of a Ph.D. thesis in the University of London. It was completed during the tenure of a Research Assistantship at The Polytechnic, Regent Street, London W. 1.

This review highlights published research on the principal entomogenous nematodes that have potential as biological control agents of insects. The life-cycles and status of promising members of the families Allantonematidae, Diplogasteridae, Heterorhabditidae, Mermithidae, Neotylenchidae, Rhabditidae, Sphaerulariidae, Steinernematidae and Tetradonematidae are discussed. Emphasis is placed on attempts to control insect populations with these nematodes. Mass propagation of the Steinernematidae and Mermithidae are also discussed, including current in vivo and in vitro rearing systems. A number of these nematodes show promise as biological control agents but commercial development has been slow because of environmental limitations, host specificity and inherent problems associated with manipulation of living organisms. Although some of these nematodes have been considered for commercial preparation, it appears that they will remain ‘on the shelf’ until the need for such biological control provides small businesses with the incentive to make them available for general use.

A method is described for producing unisexual infections of N. brasiliensis in rats; this method was used primarily to obtain populations of virgin adult females. Experiments were carried out in which male worms were introduced to virgin females in the rat small intestine. The worms were recovered after periods varying from 30 min to 22 h and the females were examined for fertile egg production or other evidence of insemination.

In some experiments a few females were inseminated within 30 min of being mixed with males, but for reliable results a period of over 1 h was necessary. Sperm were first deposited along the ventral wall of the vagina and there was evidence that a single insemination could fill the vagina. After 4·5 h the majority of females had been inseminated and this period was long enough for sperm to reach the seminal receptacle in one female. A minority of females had a few fertile eggs in the uterus by 5·5 h, and fertile eggs were being passed by 6·0 h after the introduction of males.

Small numbers of males were introduced to an excess of virgin females in order to obtain information on the sexual capacity of males. These experiments indicated that males could, on average, fertilize one female every 2 h during the first 15–20 h. This potential was shown to be greatly in excess of the minimum requirements for maintaining the maximum fertile egg output of females in normal infections.

A piroplasm was isolated from a wild-caught Psammomys obesus from the lower Jordan Valley. In wild-caught Psammomys the infection is submicroscopic or of very low intensity, but rises sharply following splenectomy. The animal from which the piroplasm was isolated died with a 44 % parasitaemia and haemoglobinuria, following splenectomy.

The piroplasm was transmissible to clean, laboratory-bred Psammomys, to hamsters and Meriones. It was not transmissible to, or gave rise only to transient infections in, adult mice, rats, Mastomys, Acomys and Arvicanthis. Suckling mice and rats showed low parasitaemias for a few days, although division forms of the parasite were observed.

No protective cross-immunity with Nuttallia danii was observed.

On the basis of its measurements, spectrum of infectivity to experimental animals and absence of cross-immunity with N. danii, the piroplasm of Psammomys is considered to be a new species.

The name Nuttallia meri, sp.nov. in memory of the late Prof. Gr. G. Mer, is proposed for this piroplasm of Psammomys obesus.

I should like to express my appreciation of the excellent technical assistance provided by Mrs Miriam Sarfatti and Mr A. Bortinger, and to thank Dr Y. Schlein for his help with some of the drawings. I am particularly indebted to Dr A. Hadani of the Kimron Veterinary Institute for providing me with Meriones and testing N. meri in his laboratory.

This study was supported by the Reubin Kunin and Samuel Lunenfeld Medical Research Foundation - to which grateful acknowledgement is made.

Two new species of the genus Hoplopleura are described from two closely related species of the genus Mus. H. ramgarh sp.nov. was found parasitizing Mus platythrix Bennett, 1932, in the Western Himalayan region in North India and in the Western Ghats in Peninsular India. H. sinhgarh sp.nov. was found parasitizing a species of the genus Mus, closely related to M. platythrix, and occurring sympatrically with it. The exact taxonomical status of this rodent species is still under investigation. The occurrence of two distinct species of lice on closely related sympatric populations of these mice has given an indication of their being two distinct taxa, a fact later supplemented by some consistent but not easily delineable skin and skull characters.

Groups of R. appendiculatus ticks infected with T. parva were irradiated at doses varying from 0 to 32 krad and then applied to rabbits; 3 and 4 days later their salivary glands were removed, processed and examined. Increasing doses of irradiation resulted both in a decreased infection rate of ticks and a decrease in the number of parasite masses observed in infected ticks. No normal parasite masses were seen after doses of 4 krad or above.