The total lipid content of the dry weight of whole cysts and 2nd-stage juveniles (J2) of Globodera rostochiensis was 17·1% in dry cysts, 20·9% in cysts soaked in distilled water (DW), 20·3% in cysts that had been in potato root diffusate (PRD) for 7 days, 7·3% in cysts that had been in PRD for 28 days and 29·2% for hatched J2. The fatty acid composition of the total lipid did not differ between dry cysts, cysts in DW and cysts in PRD for 7 days. However, major differences in the fatty acid composition of all lipid classes were found between rehydrated cysts in PRD and freshly hatched J2. After hatching, the degree of saturation and the percentage of monounsaturated fatty acids decreased and the percentage of polyunsaturated fatty acids increased considerably, especially in the free fatty acid fraction, where C20[ratio ]1 showed an 8-fold decrease and C20[ratio ]4 a 33-fold increase. There was a difference in the fatty acid composition of cysts in PRD for 7 days and cysts in PRD for 28 days (after most of the J2 had hatched); with increased time in PRD the percentage of polyunsaturated fatty acids increased and the percentage of monounsaturated fatty acids decreased in all lipid classes. Differences in the fatty acid profiles between cysts in PRD for 28 days and hatched J2 were found mainly in the free fatty acid and the non-acidic phospholipid fractions. The free fatty acid fraction of the cysts was dominated by monounsaturated fatty acids (52%), whereas the same fraction of hatched J2 contained large amounts of polyunsaturated fatty acids (60%). These polyunsaturated fatty acids, especially C20[ratio ]4, might play an important part in nematode–plant interactions during infection.

Sulphaquinoxaline fed at 0·0125%, w/w, in the food principally affects the development of the second generation schizonts of Eimeria adenoeides in turkey poults. Amprolium, at the same concentration, acts on the first generation. Both drugs appear to exert some effect on gametogony. The activity of sulphaquinoxaline against this species is inhibited by p-aminobenzoic acid, and the activity of amprolium by thiamine.

We are grateful to Mrs B. M. Mitchell and Miss C. Hitchcock for technical assistance and to Mr A. D. Speed for the histological preparations.

Habitat and Record. During November 1924, by the courtesy of Seizo Takeda, I received from the Yogyo Shikenjyo (Piscicultural Experiment Station) at Kitajima near Toyohashi, Japan, the head of a small Japanese eel, Anguilla japonica, whose buccal cavity appeared to be completely filled with about forty parasites belonging to the genus usually known as Lernaeocera, but to which Wilson (1917, p. 3) has given reasons for restoring the name Lernaea Linnaeus. (See Note, p. 251.)

Toxascaris versterae sp.nov. from hyenas in South Africa is described. T. versterae is compared with Toxascaris leonina, the only other member of the genus.

I thank Professor J. F. A. Sprent for his advice and criticism. This work was supported by grants from the Australian Research Grants Committee and from the U.S. Department of Health, Education and Welfare, No. AI-07023–03.

When studying a collection of ticks sent to us by Dr G. I. Sorokoumov from Turkestan, we observed several specimens which presented a remarkable appearance. Their bodies were covered with numerous oval, whitish, well-defined elevations with a glossy surface. We could find no reference to such a condition in the literature on ticks. A disease in Rhipicephalus bursa nymphs, observed by P. Schulze in 1925, and supposed to be due to a fungus, offers no similarity.

Evidence for the presence of adipokinetic hormone/hypertrehalosaemic hormone (AKH/HrTH)-like peptides in the parasitic nematodes Ascaridia galli and Ascaris suum has been obtained using insect bioassays which measure hyperglycaemic responses to peptides belonging to the AKH/HrTH family of insect hormones. A peptide fraction extracted from heads and tails of Ascaridia galli evoked a dose-dependent hyperglycaemic response when injected into the cockroach, Periplaneta americana. Maximal bioactivity was obtained with material that was equivalent to 38 mg (wet weight) of nematode. Bioactivity appeared to be highest in extracts from heads and tails of both male and female worms and could be fractionated into at least three peaks of hyperglycaemic activity by reversed-phase high-performance liquid chromatography. An extract from heads and tails of A. suum also evoked a hyperglycaemic response when injected into the cockroach, Blaberus discoidalis. The bioactivity was inactivated on incubation with pure endopeptidase 24.11, confirming the peptidic nature of the bioactive material. These results provide evidence for the existence of peptides related to the insect AKH/HrTH family of peptides in parasitic nematodes.

This collection, among others, was made for and kindly presented to me by Miss Miriam Rothschild during her visit to the Zoological Station, Naples, in April 1934.

During the early part of 1928, a census of the rookeries in the Oxford district was carried out by the Oxford Bird Census organised by Mr E. M. Nicholson. This work raised a number of problems, of which one of the most important was that of natural checks to the numbers of rooks. Although shooting of the young rooks is one of the greatest checks on their population, Mr Nicholson's observations showed that there must also be a mortality amongst the nestlings. Lewis (1925, 1926 b) has shown that gape-worms are common in starlings (Sturnus vulgaris), and it seemed possible to us that this parasite might also be sufficiently common in rooks to cause deaths among the young birds. The gape-worm had already been recorded from the rook by Lewis (1926 a) and Baylis (1928), so that the possibility seemed well worth investigating.

Temperature can be a limiting factor on parasite development. Riccardoella limacum, a haematophagous mite, lives in the mantle cavity of helicid land snails. The prevalence of infection by R. limacum in populations of the land snail Arianta arbustorum is highly variable (0–78%) in Switzerland. However, parasitic mites do not occur in host populations at altitudes of 1290 m or higher. It has been hypothesized that the host's hibernation period might be too long at high elevations for mites and their eggs to survive. To test this hypothesis, we experimentally infected snails and allowed them to hibernate at 4°C for periods of 4–7 months. Winter survival of host snails was negatively affected by R. limacum. The intensity of mite infection decreased with increasing hibernation duration. Another experiment with shorter recording intervals revealed that mites do not leave the host when it buries in the soil at the beginning of hibernation. The number of mites decreased after 24 days of hibernation, whereas the number of eggs attached to the lung tissue remained constant throughout hibernation. Thus, R. limacum survives the winter in the egg stage in the host. Low temperature at high altitudes may limit the occurrence of R. limacum.

Chicks were treated with cyclophosphamide during the first 3 days of life in order to effect chemical bursectomy. They subsequently showed a reduced capacity for the production of serum agglutinins to Brucella abortus and immunolysins to sporozoites of Eimeria tenella. They also developed a reduced immunity to E. tenella or E. maxima compared with that produced in normal birds. The evidence provided by these experiments for the role of circulating antibodies in immunity to coccidiosis is discussed.

An oligonucleotide mixture based on the 21 base pair repeat sequence of Plasmodium falciparum was covalently coupled to biotin and used as a probe to detect P. falciparum DNA. The limit of detection was 10 ng. This method was further developed as a fingerprint assay for parasite strain typing. After restrictian enzyme digestion, blotting and hybridization, distinct banding patterns were obtained for the strains tested and these were reproducible. In addition, discrete differences were found between PLF-3 S + /S-strains which may implicate genetic reorganization in the switching mechanism which occurs when parasites are passed from an intact to a splenectomized animal.

Three kinds of lice are found on horses, two belonging to the Mallophaga or scale-eating lice and one to the Siphunculata or blood-sucking lice.

A method is described for obtaining sterile second-instar larvae of beet eelworm, Heterodera schachtii Schm., and culturing them to the adult stage on sterile excised roots of sugar beet, Beta vulgaris L. It was shown that beet eelworm is a primary pathogen, for sound uninjured radicles were invaded by larvae, and normal development of adult males and females followed. No females were fertilized, and no eggs were produced, which suggested that parthenogenesis cannot occur. Eelworm development stimulated the production of lateral roots. More adult females developed on radicles inoculated 24 hr. after excision than on radicles inoculated 72 hr. after excision, which may be related to the occurrence of maximum root extension during the first few days after excision. It is suggested that there are two parts in root tissue reactions: a thickening of cell walls as a wound reaction to mechanical injury, and formation of a syncytium in response to a chemical stimulus from the eelworm.

I thank my wife for assistance with this work, which was financed by the Sugar Beet Research and Education Committee.

Kemptide (sequence: LRRASLG) is a synthetic peptide holding the consensus recognition site for the catalytic subunit of the cAMP-dependent protein kinase (PKA). cAMP-independent protein kinases that phosphorylate kemptide were stimulated in Trypanosoma equiperdum following glucose deprivation. An enriched kemptide kinase-containing fraction was isolated from glucose-starved parasites using sedimentation throughout a sucrose gradient, followed by sequential chromatography on diethylaminoethyl-Sepharose and Sephacryl S-300. The trypanosome protein possesses a molecular mass of 39.07–51.73 kDa, a Stokes radius of 27.4 Ǻ, a sedimentation coefficient of 4.06 S and a globular shape with a frictional ratio f/fo = 1.22–1.25. Optimal enzymatic activity was achieved at 37 °C and pH 8.0, and kinetic studies showed Km values for ATP and kemptide of 11.8 ± 4.1 and 24.7 ± 3.8 µm, respectively. The parasite enzyme uses ATP and Mg2+ and was inhibited by other nucleotides and/or analogues of ATP, such as cAMP, AMP, ADP, GMP, GDP, GTP, CTP, β,γ-imidoadenosine 5′-triphosphate and 5′-[p-(fluorosulfonyl)benzoyl] adenosine, and by other divalent cations, such as Zn2+, Mn2+, Co2+, Cu2+, Ca2+ and Fe2+. Additionally, the trypanosome kinase was inhibited by the PKA-specific heat-stable peptide inhibitor PKI-α. This study is the first biochemical and enzymatic characterization of a protein kinase from T. equiperdum.

A rapid, visually read, dot-ELISA developed for the detection and differentiation of trypanosome species in tsetse flies (Glossina spp.), was field tested alongside the standard fly dissection method on a ranch in south eastern Kenya. Of 104 G. pallidipes dissected, 2 were found to be infected with trypanosomes in their midguts. By the dissection method the infecting trypanosome species could not be identified, as both flies had no salivary gland infections. However, using the dot-ELISA, the 2 flies were shown to be infected with Trypanosoma congolense in their midguts. The midguts of an additional 6 (5·8%) of the 104 G. pallidipes tested positive for T. congolense in the dot-ELISA, even though no trypanosomes were seen on dissection. The infection rate for this fly species as determined using the dot-ELISA, therefore, was 7·7% for T. congolense in midgut infections compared to 1·9% identified by fly dissection. The salivary glands and mouthparts of the 6 additional tsetse flies identified by dot-ELISA were all negative as determined by the 2 techniques. None of 390 G. longipennis flies dissected and examined for trypanosomes in the midgut, salivary glands and mouthparts was shown, by this method, to be infected. Using the dot-ELISA, however, 17 (4·4%) of the flies tested positive for T. congolense in the midgut, whilst the salivary glands and mouthparts of the same flies were negative. Thus, the dot-ELISA appears to be more sensitive than the fly dissection method under field conditions. Moreover, the dot-ELISA can be performed in the field without electricity. It is simple to perform, and was not affected by high ambient temperatures (22–32°C), or by contamination of reactants with dust.

The external features, the excretory, nervous and genital systems of Phyllobothrium sinuosiceps sp.nov. (Cestoda: Tetraphyllidea) from Hexanchus griseus are described in detail, particular attention being given to the genitalia.

The species is compared with Phyllobothrium dohrnii, a well-known cestode.

The systematic position of P. sinuosiceps is discussed and the differences between P. sinuosiceps, P. lactuca and P. radioductum are tabulated.

The simple arrangement of the nervous and excretory systems, the specialized features of the genitalia and host distribution suggest that P. sinuosiceps may be one of the most primitive species belonging to the family Phyllobothriidae.

Studies were performed to identify specific parasite proteins synthesized within Plasmodium knowlesi-infected rhesus erythrocytes. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of whole parasites freed from the host erythrocyte by immune lysis, of membranous and cytoplasmic parasite fractions, and of isolated merozoites, detected several parasite-specific components after Coomassie Blue staining of the separated proteins. However, significant contamination with host erythrocyte material generally occurred, particularly in the whole parasite and parasite membrane preparations. Improved identification of plasmodial proteins was subsequently afforded by a radioisotope labelling technique in which parasitized erythrocytes were cultivated in vitro with [3H] isoleucine prior to electrophoretic analysis. Of 11 principal labelled peaks ranging in molecular weight from approximately 17000 to 145000 which were detected upon electrophoresis of whole parasites harvested from culture, all were observed in the cytoplasmic fraction while at least 5 were also associated with the membranous cell fraction. Analysis of different developmental stages of the intra-erythrocytic parasite revealed no significant stage-specific qualitative variations in the electrophoretic profiles. Quantitatively, however, the middle to late trophozoites incorporated more [3H] isoleucine into protein than the other intra-erythrocytic stages. Analysis of merozoites purified from labelled schizonts showed a protein pattern similar to the other stages. This confirmed that host components did not contribute to the labelling pattern and that none of the labelled proteins were specific to the residual cytoplasm remaining after merozoite formation.

Macrogametogony and the formation of the oocyst wall has been examined in Eimeria acervulina. Macrogametes develop within a parasitophorous vacuole. Within the cytoplasm can be observed wall-forming bodies of Type I (WFBI). and Type II (WFBII), a nucleus, mitochondria, canaliculi and polysaccharide granules. WFBII are unusual in possessing a membrane internal to the granular endoplasmic reticulum. Formation of the outer layer of the oocyst wall is preceded by the separation of a veil membrane, and accompanied by morphological changes in the WFBI. WFBI material is deposited between the veil-forming membrane and the two cytoplasmic membranes. A newly formed membrane divides this outer layer during its early development. The inner layer of the oocyst wall is formed from WFBII material which is deposited between the cytoplasmic limiting membranes. The outer layer of the oocyst wall consists of granular and osmiophilic parts, but the inner layer of the wall is homogenous.