Habitat and record. The animal under consideration, a copepod of the Family Caligidae, has up to the present received three notices: by Norman and T. Scott (1906), A. Scott (1907), and T. and A. Scott (1913). (For further particulars see References at end of this paper, p. 409.) Norman and Scott stated that “the specimens were taken forty years ago on the dory by Laughrin, and by him sent to A. M. N.” Consequently, the specimens were forty years old before they were described, which would, even in the absence of other reasons, excuse a little scepticism as to the description. Scott gives a bare record of capture, with a copy of Norman and Scott's diagrams. These diagrams and the original of Norman and Scott are republished by Scott and Scott with the addition of a few errors. Considering these facts, and also that no satisfactory description is given of the appendages of the male, or of the maxillae or swimming legs of the female, and that the animal is very common, occurring on nearly every dory, I feel that there is some justification for a further description.

The differences noted between these Sarcoptes from cattle and those from the horse, described by Buxton, are as follows:

There are two lateral setae in all stages. The spines are notched or V-shaped at the ends. There are three cones in the larva as well as in all other stages. There is a pair of setae analogous to that found on the genital apron of the male at the corresponding location in the immature female. In the immature female the ridges on which are located the third ventral setae (V 3) run backward without returning forward on the opposite side. In the adult female, immature female and male, the two short setae on the terminal joint of the first leg, P 7 and 8, are represented by a single seta on the second leg. The third leg in all stages is furnished with four short setae on the terminal joint. The end joint of the fourth leg of both adult and immature females has four short setae. In the nymph none are present on the fourth leg.

For the opportunity to examine the material on which the following descriptions are based I am indebted to the courtesy of Dr P. A. Buxton and Miss E. Sikes of the London School of Tropical Medicine, where the life-history of certain fleas is being studied. A detailed examination of the parasite showed it to be referable to the Pirenine tribe of the Miscogasteridae—a family of Chalcidoid wasps. The genus and species appeared to be new. The fact, however, that the parasite had been bred from a species of flea known to have been recently introduced into Britain suggested the advisability of comparison with American representatives of the Pirenine group. This has now been done by my friend Mr A. B. Gahan of the Bureau of Entomology, Washington, D.C., to whom my hearty thanks are due. As the result we are agreed that a new genus is required. Bairamlia n.g. has obvious affinities with Pirene Hal., but differs in antennal, neurational and propodeal characters. Ecrizotes Forst. (fide A. B. Gahan) may also be a nearly related genus. genus. As regards the species, I am satisfied that it is very different from anything described by Walker of which material is still extant in the British Museum. Mr Gahan, however, tells me that Pirene marylandensis Gir. (Canad. Ent. 48, p. 116, 1916) is a congeneric though distinct species.

In Cameroon, there is a national programme engaged in the control of schistosomiasis and soil-transmitted helminthiasis. In certain locations, the programme is transitioning from morbidity control towards local interruption of parasite transmission. The volcanic crater lake villages of Barombi Mbo and Barombi Kotto are well-known transmission foci and are excellent context-specific locations to assess appropriate disease control interventions. Most recently they have served as exemplars of expanded access to deworming medications and increased environmental surveillance. In this paper, we review infection dynamics through time, beginning with data from 1953, and comment on the short- and long-term success of disease control. We show how intensification of local control is needed to push towards elimination and that further environmental surveillance, with targeted snail control, is needed to consolidate gains in preventive chemotherapy as well as empower local communities to take ownership of interventions.

The isometric mechanical properties of diaphragm muscle were studied in mice infected with either Trichinella spiralis or Trichinella pseudospiralis. Measurements of muscle stress were taken at 15, 20, 30 and 40 days post-infection. Infected diaphragm muscle showed a significant (P < 0·001) reduction in muscle stress during both twitch and tetanic contractions when compared with muscle from control animals. T. spiralis caused a significant reduction in resistance to muscle fatigue. The consequences of these changes in muscle function to host pathology are discussed, and related to previous work on the effects of Trichinella on host biochemistry and the immune response.

The distribution of Tetrahymena limacis in its natural host Deroceras reticulatum, and the tissue responses to infection are described. Contrary to previous observations, T. limacis occurred throughout the tissues and organs of its host; the organisms were especially numerous in the kidney, the mantle shield, and in grossly visible papules on the external epithelium. Aspirates from such papules yielded numerous ciliates.

T. limacis elicited a considerable pathologic response and appeared to contribute to an increase in morbidity and mortality among slugs. Tissue responses were focal (fibrotic encapsulation of isolated organisms) and diffuse (necrosis, mechanical tissue destruction, and metaplasia). Efforts to establish infection in seven species of molluscs other than D. reticulatum were unsuccessful.

An extramolluscan cyst stage of T. limacis is reported for the first time. Both resting and reproductive cysts were observed. Since free-swimming trophozoites of T. limacis are not long lived, the organism is more likely an obligate rather than a facultative parasite of molluscs. Observations also suggest that slugs are infected via the respiratory pore rather than orally.

It is a pleasure to acknowledge the aid and counsel given by Dr J. O. Corliss in identifying the ciliate and to Miss Lorin DuBois for technical assistance.

African representatives in the family Microphallidae (Trematoda) are recorded, and descriptions of five new species are given. Collections made on the Kenya coast showed: (Aves) Crocethia alba infected with Microphallus kenyensis sp.nov.; Encocotyle africanus sp.nov., and Maritrema sethsmithi sp.nov.; Tringa hypoleucos and Numenius phaeopus infected with Diacetabulum curvicolon Belopolskaia, 1952; (Reptilia, Scincidae) Ablepharus boutonii africanus infected with Levinseniella heardi sp.nov., Maritrema sethsmithi sp.nov. and Maritreminoides ablephari sp.nov.

Patti Hirst and Alma Smith assisted with preparation of the plates. R. W. Heard III and S. Deblock loaned material and made helpful comments on the reproductive structures in the genus Levenseniella.

Curie-point pyrolysis gas-liquid chromatography (PGLC) was used to detect gross chemical differences between the 8 European pathotypes of the potato cyst nematodes Globodera rostochiensis and G. pallida. No qualitative differences were seen with either flame ionization or flame photometric detection systems, although quantitative differences between pathotypes were detected. Cluster analysis of these differences failed to group the pathotypes into species, but separation of some economically important pathotypes was achieved. The potential of PGLC for nematode identification is discussed.

The capillariid nematodes present in avian hosts collected in Palawan and Borneo are recorded and described. Three new species are established, Capillaria javanensis from Dinopium javanense everetti, Drycopus javanensis hargitti, Mei-glyptes tukki tukki and Megalaima chrysopogon chrysopsis, Capillaria pitti from Pitta sordida sordida, Copyschus niger niger, Copyschus saularis and Chalcophaps indica indica, and Capillaria anthracocerosi from Anthracoceros marchei. Capillaria tridens and C. madseni are recorded from new hosts.

We wish to acknowledge the field support by Dr D. S. Rabor, Department of Biology, Silliman University, Damaguete City, Negros Oriental, Republic of the Philippines, and the technicians of the Parasitology Department of Naval Medical Research Unit No. 2 for general assistance in procurement and examination of hosts. The authors are indebted to Messrs H. G. Deignan (deceased) and George Watson, U.S. National Museum, Washington, D.C., as well as to Dr Rabor for identification of hosts. Dr B. J. Myers assisted with the initial handling of the spe

Initial work for this study was supported by funding under Public Law 480, Section 104(c), by funds provided by the Bureau of Medicine and Surgery, Navy Department Work Unit MR 005.20–0098, by contract no. NR 103–690/N 0014–66–C 0094, between the Office of Naval Research, Department of the Navy and the Southwest Foundation for Research and Education, and grant no. 5 P01-GM-13252–02 from the National Institute of Allergy and Infectious Diseases, DHEW. Final efforts were sponsored by the Department of the Army, contract no. DADA 17–68-C-8094.

Suckling rats of various ages were infected with large doses of the 'RH' strain of Toxoplasma gondii either by intraperitoneal injection or by feeding. Among the intraperitoneally infected rats of different age-groups, the percentage of survival remained low up to 23-day-old rats, after which it increased sharply. The percentage of infection was 100%. Among the rats infected by feeding, the percentage of survival was low in rats up to 5 days old at the time of feeding, after which it increased sharply and remained more or less constant. The percentage of infection decreased gradually with increasing age. These results are discussed in the light of previous knowledge.

My thanks are due to Professor P. C. C. Garnham for his interest in this study and for providing me with the facilities. My thanks are also due to Mr Z. W. Pokrzywnicki of the Department of Bacteriology for his assistance with the Polish literature.

The routes of penetration and the strategies of invasion of Schistosoma japonicum miracidia in the snail vector Oncomelania hupensis were observed in a histological study. In all species of the genus Schistosoma, it is usually assumed that the miracidia achieve penetration through the tegument. Our results showed that at least 57% of S. japonicum miracidia penetrated the snail by natural openings (branchial cavity, mouth and rectum). Throughout the invasion phase, the larvae were observed in all the tissues and organs with the exception of the genital gland. The spatial distribution of parasites in the snail revealed that the migration towards the visceral organs such as the kidney, heart and sinuses (which are the most usual microhabitats of the mother sporocysts of S. japonicum) appeared to take place via the circulatory system. Using natural openings as routes for penetration probably provides a selective advantage in a host–parasite system in which the target mollusc is amphibious: we presume that the miracidia inside these natural openings are protected against desiccation when the snail leaves the water, and that they can subsequently invade the tissues.

1. Examination of dividing trophozoites of E. invadens revealed that the peripheral granules did not contribute directly to the formation of chromosomes. Material for the chromosomes seemed to be derived from the karyosome and the perikaryosomal particles. No centrioles and spindle mechanism were noticed.

2. The nucleus showed Feulgen-positive material at all stages; in the interphase the reaction was faint because of the poor staining of the karyosome and widely dispersed perikaryosomal particles. The intensity of the staining reaction increased with the onset of division and continued so till late anaphase.

3. Nuclear division in the cyst was found to be different from that of the trophozoites and involved the formation of a typical spindle.

4. Karyosomes of the nuclei of the uni-, bi-, tetra-nucleate cysts were all positive to Feulgen staining.

5. Observations on amoebae undergoing cytokinesis showed that the process of division supports the amoeboid movement theory of cleavage put forward by Chalkley (1935, 1951).

Thanks are due to Dr P. Tate for constant guidance and encouragement during the course of this work and to Dr E. W. McConnachie for kindly giving the cultures and for critically reading through the manuscript. The work was carried out during the tenure of a Royal Society and Nuffield Foundation Commonwealth Bursary.

Observations are reported on the fluctuations in populations of gastro-intestinal nematode parasites in 68 calves on two dairy farms in Fiji based on fortnightly faecal worm egg counts over a 3-year period. On one of the farms the calves began to graze soon after birth; on the other farm they were reared indoors until they were weaned at 6 months of age.

The important species were Cooperia spp., Bunostomum phlebotomum, Haemonchus placei, H. similis and Oesophagostomum radiatum. Only small numbers of Trichostrongylus spp., Mecistocirrus digitatus and Neoascaris vitulorum were present.

Potentially pathogenic worm burdens were only found in young cattle, mostly between 2 and 15 months of age. Faecal egg counts for each parasite species rose independently to a peak and then declined to low levels. For most species there was a close relationship between the time at which the peak faecal egg count occurred and the age of calves on the same farm, irrespective of the season in which the calves began to graze. This is considered to be due to the high rainfall and constant high temperatures throughout the year resulting in at least minimal favourable conditions for the development and survival of the pre-parasitic stages of all species in all months of the year. It is concluded that the succession of species which occurred must be strongly influenced by intrinsic factors in the life-history of each parasite.

Tere were differences in the levels of peak egg counts between groups of calves which began to graze in different seasons but almost all parasite species examined were affected equally. The lowest levels were recorded in calves which were first exposed continuously to infection at the beginning of the dry season and the highest levels in those exposed at the beginning of the wet season.

Protection of calves from parasite infection, by indoor rearing until weaning at 6 months of age, did not confer any striking advantage as the acquisition of potentially pathogenic worm burdens was merely delayed.

The results are discussed in the light of recent theoretical concepts regarding the immunological control of helminth parasite infection.

I am indebted to Mr A. E. Harness of Wainivesi for permitting observations to be made on his dairy farm, to Deo Raj Singh and Ram Kumar for technical assistance, and to Dr D. F. Stewart and Dr J. K. Dineen of the McMaster Laboratory for their criticism of the manuscript. My thanks are due to Miss Suzanne Dodd and Mr I. T. Roper of the McMaster Laboratory for the preparation of the figures. The permission of the Director of Agriculture, Fiji, to publish this paper is gratefully acknowledged.

Experiments to investigate the linked metabolism of L-serine and L-alanine by Moniliformis moniliformis in vitro were carried out by incubating adult worms aerobically for 3 h at 37 °C in Tyrode’s solution containing L-[U-14C]alanine and other amino acids. When present in the medium alone, alanine was totally removed by the worms and metabolized almost entirely to ethanol and a compound identified as carbon dioxide. When present in the medium with serine and no other amino acids, alanine was largely metabolized as before but additional alanine, believed to originate from serine, was excreted. The same results were obtained with serine and 16 other amino acids in the incubation medium.

Glucose uptake was examined in adult specimens of Proterometra macrostoma (Trematoda: Digenea) recovered from the stomach (endoparasites) and gills (ectoparasites) of longear sunfish, Lepomis megalotis. The endoparasitic forms transported glucose directly through the external body surface by Na+-independent, facilitated diffusion, but the ectoparasites absorbed glucose by free diffusion alone. To determine how this transport function is regulated, cercariae were incubated in solutions having Na+ concentrations normally found in fish gut (50 mM) and in fresh water (0·5 mM). Glucose transport capacity was retained in 50 mM Na+, but disappeared in worms incubated for 1–3 days in 0·5 min Na+. Returning worms from the latter solution to one containing 50 mM Na+ fully restored glucose transport within a day. By contrast, incubation up to 5 days in 0·5 mM Na+ had no effect on glucose transport in endoparasitic adults of P. macrostoma and cercariae of P. edneyi. Thus, cutaneous sugar transport function in the migrating larva of P. macrostoma is subject to indirect regulation by environmental Na+.

1. The weight of blood ingested by all stages of H. anatolicum anatolicum has been determined and from the results a direct relationship appears to exist between the weights of replete adults and their blood content. In engorged nymphs the relationship was subject to some variations, while in fully fed larvae no such correlation was apparent, indicating the ingestion of a large proportion of extravascular fluids.

2. It was found that all instars concentrate the imbibed blood by the elimination of water. In larvae the concentration is by a factor of at least 5·25, in nymphs 3·4, in females 2·1 and in males 1·4.

3. A correlation was found between the external colour of fully engorged larvae and the quantity of blood imbibed.

I wish to thank Dr R. P. Chaudhuri for providing the original specimens of H. anatolicum anatolicum from which the culture was started, and Professor Don. R. Arthur for reading the manuscript and for his advice and assistance.

Cells of Leishmania donovani in co-culture with Trypanosoma brucei, were severely affected in their growth, resulting in swelling and subsequent lysis. Similar effects were also observed when Crithidia luciliae or Phytomonas sp. were co-cultured with T. brucei. Direct contact between the cells under investigation and T. brucei was necessary because T. brucei did not hamper the growth of the other trypanosomatids, when separated by a filter with 0.2 μm pore size. Examination of this phenomenon at the ultrastructural level, in a co-culture of L. donovani and T. brucei, suggests that the plasma membrane permeability is increased in the former, as a result of a close cellular contact between the two cell types.

As animals we have been a remarkably successful species; but also as animals we are vulnerable to environmental, in particular climate change. Such change is accelerating as a result of human activity, and global warming may already be taking place. Although we can foresee the trends, we cannot yet be specific about the results. Change usually proceeds by steps rather than gradients. But warming would probably include new risks to human health and contribute to an increase in human displacement. Of course climate change is only one among other complex problems facing human society, but it is closely related to them all, including population increase, environmental degradation and loss of biodiversity. We cannot prevent global warming but we can anticipate and mitigate some of its worst effects. Peoples and governments still need persuading of the need for action and of the magnitude of the issue at stake.

In a survey on the worm parasites of cats in Calcutta, Chandler (1925) mentioned the common occurrence in dogs also of Echinochasmus perfoliatus (Ratz, 1908) which has also been listed by Bhalerao (1935) in cat, dog and man. According to Verma (1935), the dogs at Calcutta harboured three distinct flukes—a species of Echinochasmus, a heterophyid and a third species described by him under a new genus, Episthochasmus, as E. caninum. In a survey of the helminth parasites of pariah dogs examined at Calcutta, Mapleston & Bhaduri (1940) included Echinochasmus sp. amongst the six new records from India. Chatterji (1954) regarded Episthochasmus as a synonym of Episthmium Lühe, 1909 and Stephanoprora Odhner, 1911, Echinochasmus and Episthmium Lühe, 1909 as subgenera of Echinochasmus. A new species, based on two specimens collected from the intestine of pariah dog at Allahabad, was described as E. (Echinochasmus) canai. Relying on the character of the forward extension of vitelline follicles, Stephanoprora was to include forms with vitellaria extending to the posterior margins of anterior testis, Echinochasmus forms with vitelline follicles extending beyond the anterior testis but not anterior to the anterior margin of ventral sucker and Episthmium forms with follicles extending beyond the anterior margin of this sucker. Thus, Verma's species was named as E. (Episthmium) caninum.