Le présent ouvrage est consacré à la caractéristique de quelques espèces de Nématodes d'oiseaux, trouvés sur le territoire de l'Empire de Russie. La plupart des formes décrites ici m'ont été gracieusement données à étudier par le Professeur de l'Académic Impériale Militaire de Médecine N. A. Cholodkowski, et je saisis l'occasion de lui exprimer ma plus sincère gratitude.

There are few, if any, authenticated records of fossil helminths or even of the hard parts of ectoparasitic monogeneans. This means that theories of helminth evolution can be based only on indirect evidence and are unlikely to be confirmed or refuted by palaeontologists.

Currently three main areas of study provide evidence of evolutionary trends: (i) morphology, in its broadest sense; (ii) life-history studies; (iii) host spectra and geographical distribution.

The activity of 12 anticoccidial drugs against an embryo-adapted strain of Eimeria tenella has been investigated. After seven and five serial passages respectively, in the presence of drug, resistance was developed to methyl benzoquate and buquinolate. A strain of E. tenella made resistant by exposure to drugs in chickens was resistant to the same drugs when evaluated in infections of chick embryos. This relatively simple technique would appear to offer advantages over existing methods for the study of drug resistance.

In spite of the continuing need for new and improved anti-protozoal drugs for use in man, a considerable contraction of industrially based research on anti-protozoal drugs has occurred in recent years. Newton (1983) reviewed the reasons for this decline and presented a compelling argument that fundamental research on the biology of the parasites is essential for the discovery of leads for the development of a new generation of drugs – a rational chemotherapy. The rapid advance in knowledge of the biochemistry of parasitic protozoa which has occurred in recent years has provided a number of potential leads to new drug development and has permitted a greater understanding of the mode of action of many current drugs. The account of these advances which follows is necessarily selective and relates to protozoan parasites of man.

The inner cyst tissue development is anteriad and centripetal. The cells produce lamellar extensions which assume parallel alignment. The first contact points (approximately 4 days post-infection) establish heptalaminar (gap) junctions. Lamellar attenuation results in a decreased intercellular space, and at 5–6 days pentalaminar junctions (with fused outer plasmalemma leaflets to give an electron-dense, approximately 3 nm wide O–O line) occur. This is the first maturation (Ml) stage. The O–O lines are permeable to lanthanum, and evidence of their possible transformation from heptalaminar junctions is presented. Continued lamellar attenuation, associated with scolex retraction and subsequent growth, results in cytoplasmic occlusion and contact between the inner leaflets of the same lamella. The resultant electron-dense I–I line is approximately 3 nm wide; the O–O line is now less electron-dense and thinner (approximately 2 nm). This final maturation (M2) stage, resembling vertebrate myelin, occurs over limited areas; closely adjacent regions either remaining at the M1 stage, or not displaying junctional complexes. Since in vivo and in vitro excystment can occur before the M2 stage, the inner cyst tissue is not considered to be protective against the definitive host. That the tissue may function in limiting nutrient flow, thus regulating the size of the presumptive adult, is discussed.

Demodex carolliae, a parasite of the bat Carollia perspicillata, is described for all stages of its life cycle. The sequences and adaptive features of this life cycle are detailed. Some information is presented on the population structure and the pathogenicity of this species.

This research was supported in part by Grant W83–1 to Dr F. Lukoschus from the Netherlands Foundation for the Advancement of Tropical Research (WOTRO).

The major glycoprotein of the sheath of Litomosoides carinii microfilariae (gp22) was analysed for its amino acid and amino sugar composition. It is rich in proline, glutamine/glutamic acid and glycine and contains (N-acetyl)galactosamine. The N-terminal amino acid sequence was determined up to position 37. It consists of a group of 6 repeats of the pentapeptide sequence methionine-glycine-proline-glutamine-proline with two minor modifications in repeats 3–6, while the first two repeats follow the general pattern more loosely. Identical N-terminal amino acid sequences were found in at least two other sheath polypeptides (33 kDa, 39 kDa). Antisera prepared against 3 overlapping synthetic peptides corresponding to the amino terminus of gp22 recognized different epitopes. They all reacted with identical patterns of sheath polypeptides. The antisera failed to recognize antigens of 4th-stage larvae of L. carinii. In contrast, cross-reacting epitopes were detected in other parasite stages. Antisera reacted with material surrounding embryos and microfilariae in the uterus of females, and caused patchy fluorescence on the sheath of blood-derived and in vitro-released microfilariae.

When ring-stage parasites are grown to the late trophozoite stage in vitro, the incorporation of [3H]adenosine into parasite DNA and RNA is in the ratio of ~ 1:1·5 and not 1:4 as expected from direct biochemical analysis of the parasite. A method is described by which large quantities of infected blood can be grown in vitro from the ring to the trophozoite stage thus allowing direct biochemical analysis of parasites grown in vitro. The results of direct biochemical analysis indicated that parasites grown in vitro have similar DNA and protein contents to those grown in vitro but that RNA contents are much less in vitro. Quantitative histochemical studies also indicated a deficiency in RNA in parasites grown in vitro. It is concluded from the evidence of three distinct methods that RNA synthesis is defective during the first asexual cycle in vitro. In the second cycle all three macromolecular biosyntheses studied are reduced when compared to the first so that the actual rate of RNA synthesis is further reduced when compared to that in vitro. It is suggested that the successive decrease in RNA synthesis parallels the reduction in multiplication obtained on subculture of the parasite.

1. The means of attachment of the mite Myocoptes musculinus to the hair of the host, the mouse, and the sites where it is located are given.

2. Normal and skin infected with M. musculinus of young (6–8 weeks) and adult (6 months) mice is treated with colchicine and examined histologically.

3. Infected skin shows a mitotic count of approximately four times that of normal skin in the adult; there is no appreciable difference in the young.

4. Acaricides used to control the mite were benzene hexachloride (0·015%), dieldrin (0·015%), arsenic and sulphur mixture (0·018% arsenic), piperonyl butoxide (5%) and dimethylphthalate (100%); the latter being the most efficacious.

5. It is established that the drugs had no effect on the rate of division of the cells of the malpighian layer of the skin.

6. The number of Myobia present increases as the Myocoptes are killed unless dimethylphthalate, an oily liquid, is used at intervals.

7. Diet in conjunction with signs of mange is discussed.

8. Carriers of M. musculinus are given.

I wish to thank Cooper McDougall for supplying the materials used in dipping and swabbing, and the Infestation Control Laboratory of the Ministry of Agriculture for supplying me with a number of specimens of wild mice from different parts of the country. I am also grateful to the Council of the Royal Free Hospital School of Medicine for facilities for carrying out the work; and to Dr A. M. Hughes for her helpful guidance at all stages of the work and especially for reading the paper.

1. The coccidial parasites (Eimeria acervulina and E. mitis) cause a recrudescence in chicks harbouring chronic infection with Plasmodium juxtanucleare.

2. E. acervulina causes higher levels of parasitaemia in P. juxtanucleare infections in chicks if the coccidial infection is produced during the prepatent period of malaria, but it does not affect the length of patent and prepatent periods or raise the mortality rate among infected chicks.

3. E. acervulina induces a severe fatal relapse in chicks harbouring latent P. gallinaceum infections.

I wish to express my sincere thanks to Professor P.C.C. Garnham who supervised this work, and Dr R. Lainson who helped in identification, isolation of the coccidial parasites and the establishment of infection in clean laboratory-bred chicks.

The tegumental surface of Schistosoma margrebowiei as viewed by scanning electron microscopy is described. Both spined and unspined tubercles were found on the dorsal and dorso-lateral surfaces of sexually mature (in copula) male worms. Unpaired males lacked spined tubercles and the development of the spines is considered to occur only when worms are in copula. The females lack tubercles. The importance of tubercle structure in the identification of schistosome species and the effect of sexual maturity on their development is discussed.

This communication is the first of a series dealing with Mallophaga from Australian marsupials. We had hoped to prepare a single monographic work on the Family Boopidae, but the carrying out of this plan has been prevented by a variety of causes, and we think it advisable to publish piecemeal the notes and descriptions that we have accumulated during the last six years. There has of late years been a recrudescence of interest in the Mallophaga, and a considerable number of students are now investigating the group. Little has been published upon the very distinct family which is characteristic of Australian marsupials, and it is important that students of the group should have diagnoses of the family, sub-families, and genera, based upon an ample material, which includes all the known species, with a single exception, and more than an equal number of undescribed new forms. Such a material is at our disposal. Apart from our own collections, Mr A. S. Le Souëf has very kindly transferred to us all his Mallophaga from marsupials, including his types.

One of the earliest known Spirochaetes from Lamellibranchs was that briefly described by Certes in 1882 from the crystalline style of the oyster. Certes named the parasite Trypanosoma balbianii. In 1891 the same worker recorded the occurrence of the organism in two species of Tapes, namely T. decussatus and T. pullaster. Laveran and Mesnil in 1901 showed that Tr. balbianii probably belonged to the Spirochaetes. The organism is now known as Spirochaeta balbianii.

Schistosomes are complex parasitic helminths with discrete life-cycle stages, adapted for survival in their mammalian and snail hosts and the external aquatic environment. Recently, we described the fabrication and use of a microarray to investigate gender-specific transcription in Schistosoma japonicum. To address transcriptional differences, 8 gender-associated gene transcripts identified previously by the microarray analysis were selected for further study. First, differential transcription patterns were investigated in 4 developmental stages using real-time PCR. Subsequently, we undertook functional analysis of a subset of 4 transcripts encoding metabolic enzymes, so as to correlate gender-associated transcript levels with enzyme activity in protein extracts from adult worms. The 8 characterized molecules serve as a basis for further investigation of differential gene expression during the schistosome life-cycle and for studying the sexual dimorphism of adult worms. Continual refinement and annotation of the microarray used in the current study should support future work on these aspects.

1. The distribution of Cimex hemipterus and C. lectularius in the Sudan is described. Leptocimex boueti has been found in two localities.

2. Reasons for the distribution of the two species of bed-bug are discussed, and it is considered likely that facilities for dispersal and atmospheric humidity may have been the most important factors.

The behaviour of cercariae was recorded on video at 10, 20 and 30 °C and a combination of population and individual behavioural patterns studied. Initially cercarial populations were extremely active, individuals alternating between swimming and sinking behaviour. As they aged the percentage sinking and resting increased resulting in the establishment of a vertical distribution in the water column. An increased environmental temperature reduced the active life-span of the parasites. Over time cercarial swimming rates declined. Swimming rates increased with environmental temperature and as a result of a shadow stimulus. As cercariae aged, the duration of swimming events decreased. Post-stimulation swimming periods were significantly longer than pre-stimulation periods. Pre- and post-stimulation swimming distances also declined with age. Post-stimulation swimming distances were significantly longer than pre-stimulation distances. The sinking rates of cercariae decreased with age while sinking periods and distances increased. Data for proportional time spent swimming and the ratio of sinking to swimming events indicated that as cercariae aged, less time was spent swimming. The frequency of swimming/sinking events declined with age. The implications of this behaviour for dispersal and transmission are discussed.

Chronic quartan malarial infection has been established in the common marmoset (Callithrix jacchius). Plasniodium brasilianunm from a douroucouli monkey (Aotus trivirgatus) was used to infect splenectomized twin animals, passed to an intact animal, and then to 4 other intact adults, 2 pairs of twins. In 2 of the 4 latter animals there was continuing patency with parasitaemias of ≤0·5% parasitized erythrocytes for 30 weeks. The other 2 had lower initial levels of paraaitaemia; in 1 of these parasitaemias remained low or subpatent. All marmosets developed lymphocytosis. One animal became ill 30 weeks after infection with anaemia, weight loss and mild proteinurea, the other 3 remained well. Histological examination showed minor changes in the kidneys; spleens of infected animals showed marked follicular hyperplasia and phagocytosis of pigment. The livers showed sinusoidal hyper cellularity and pigment deposition and in splenectomized animals, a marked lymphoid follicular hyperplasia in the portal tracts.

A preliminary survey of parasites from Apodemus hebridensis, Mus musculus and Epimys norvegicus on the Isle of Lewis, Outer Hebrides, is described; also the fauna of House Mouse nests. Special discussion is given of the flea fauna, and it is shown that there is much overlapping in host relations. The original flea fauna of Apodemus on the outer islands of the British Isles is indicated.

The two filarial Nematodes known to parasitize dromedaries in Egypt are Dipetalonema evansi and Onchocerca fasciata, of which the first is the more common. Representatives of these genera also infect man and other animals and are known to be very common in endemic areas. Doubt has always arisen in the researches of those few who worked on this subject, as to the connexion of the adult Dipetalonema evansi with the microfilariae found in the blood of Camelus dromedarius and C. bactrianus.

Nine species of parasitic copepods are reported, with 3 of them being new to science. They are: (1) Chondracanthodes deflexus Wilson from Antimora rostrata Günther, Coryphaenoides (Chalinura) brevibarbis (Goode and Bean), Coryphaenoides (Nematonurus) armatus (Hector), Coryphaenoides (Chalinura) leptolepis (Günther), and Coryphaenoides (Lionurus) carapinus (Goode and Bean); (2) Chondracanthodes radiatus (Müller) from Macrourus berglax Lacepede; (3) Lernaeopodina pectinata sp.nov. from Alepocephalus agassizi (Goode and Bean); (4) Neobrachiella pinguis (Wilson) from Antimora rostrata Günther; (5) Clavella adunca (Strøm) from Macrourus berglax Lacepede; (6) Sphyrion lumpi (Krøyer) from Antimora rostrata Günther; (7) Lophoura gracilis Wilson from Synaphobranchus kaupii Johnson; (8) Lophoura pentaloba sp.nov. from Coryphaenoides (Nematonurus) armatus (Hector) and Nezumia bairdii (Goode and Bean) and (9) Lophoura tetraphylla sp.nov. from Antimora rostrata Günther. The infected fishes were collected with trawls from depths of 828 to 4815 m in the New York Bight and 403 to 1294 m near the Grand Banks (south of Newfoundland).