Here we report on the infection of captive crested geckos Correlophus ciliatus Guichenot (Reptilia: Diplodactylidae), with adults of the ascaridoid nematode, Hexametra angusticaecoides Chabaud & Brygoo, 1960 (Ascarididae). A population of captive crested geckoes became ill and died within a short period of time. Nematodes were recovered from the crested geckoes examined from within the coelomic cavity, penetrating various organs and migrating through subcutaneous tissues, as well as emerging through the geckos' skin. One gecko was treated with levamisole following surgical excision of nematodes from under the skin; this gecko survived. The potential source of the nematode infection in the captive geckoes is discussed. It is most likely that wild-caught Madagascan mossy geckoes, Uroplatus sikorae Boettger (Reptilia: Gekkonidae), introduced the infection to the colony. Molecular sequences of the nematodes are the first produced for the members of this genus. A redescription of the species and its genetic characterization based on the internal transcribed spacer sequence data is provided, suggesting some of the morphological criteria that have been used in the past to distinguish between Hexametra spp. may have been intraspecific morphological variations.

The writers (1932) have previously reported on the surprisingly great individual variability in susceptibility to infection with Eimeria miyairii which they encountered among white rats taken at random. It was learned in the study that young rats of from 65 to 149 g. in weight would eliminate from 14 to 169 million oocysts during immunisation produced by inoculation per os with 1500 sporulated oocysts daily over a period of 5 days. The question naturally arises whether different strains of the host exhibit differences in susceptibility similar to those noted in individuals.

Female characters. Head connected to the thorax by a V-shaped chitinised plate. Eyes absent. Antennae 5-jointed, the first segment strongly developed. Thorax long and narrow; metathorax distinct. Sternal plate present, long and narrow; metasternum with narrow transverse chitinised bar. Thoracic stigmata apparently absent. Fore pair of legs smaller than the mid and hind legs; mid and hind legs sub-equal, widely separated. Abdomen elongated and narrow, without sutures and tergal and sternal plates. Pleural plates present on the second abdominal segment only. Stigmata present on the third to eighth abdominal segments. Tergites and sternites each with a row of long hairs and short spines.

Habitat and record: About forty specimens, of both sexes, collected and presented to me by Miss Miriam Rothschild from a bream Abramis brama (wt. 13 lb. 1 oz.) taken from the Tring reservoir, December, 1931.

Muriel Robertson (1883–1973) was a pioneering protozoologist who made a staggering number of important contributions to the fields of parasitology, bacteriology and immunology during her career, which spanned nearly 60 years. These contributions were all the more remarkable given the scientific and social times in which she worked. While Muriel is perhaps best known for her work on the life cycle and transmission of the African trypanosome, Trypanosoma brucei, which she carried out in Uganda at the height of a major Sleeping Sickness epidemic, her work on the Clostridia during the First and Second World Wars made significant contributions to the understanding of anaerobes and to the development of anti-toxoid vaccines, and her work on the immunology of Trichomonas foetus infections in cattle, carried out in collaboration with the veterinarian W. R. Kerr, resulted in changes in farming practices that very quickly eradicated trichomoniasis from cattle herds in Northern Ireland. The significance of her work was recognized with the award of Fellow of the Royal Society in 1947 and an Honorary Doctorate of Law from the University of Glasgow, where she had earlier studied, in 1948.

The ZAP Express cDNA library was constructed using mRNA extracted from the triactinomyxon spores of Myxobolus cerebralis. First-strand cDNA was synthesized using Moloney Murine leukaemia virus reverse transcriptase. Following second-strand cDNA synthesis, the double-stranded cDNA was digested with Xho I restriction enzyme, cDNA fragments less than 400 bp were removed and the remaining cDNA was ligated with the lambda ZAP Express vector. The recombinants were packaged in vitro using Gigapack III gold packaging extract. The primary cDNA library titre contained 0·5×106 clones, with 97% recombinant and only 3% non-recombinant clones. The cDNA library was then screened using the anti-triactinomyxon antibodies. Positive clones were selected and re-screened twice more to give a final selection of 526 clones. One clone (46-5) was selected randomly and subjected to in vivo excision of the pBK-CMV phagemid from the ZAP express vector. The sequence of the entire clone was obtained using rapid amplification of the cDNA ends. A search of the clone sequence against GenBank revealed that it related to ribosomal protein L23 and it had a high percentage similarity to this protein from different species. A conserved domain for ribosomal protein L23 was also identified in the clone sequence.

Anoplura without eyes; with four segmented antennae not dimorphic in the sexes; 1 well developed sensorium on 4th antennal joint postero-basally; head considerably contracted posteriorly. Segments I–III closely united, more distinctly separated from the rest of the abdomen than the succeeding segments are inter se. 2nd sternite divided. 3rd cap-shaped.

Isospora rastegaievae undergoes its asexual development in the intestinal tract of hedgehogs by endodyogeny. Using light- and electron-microscopy it was demonstrated that daughter organisms were formed by typical endodyogeny as described for different coccidia.

1. Areas in which theileriasis occurs are characterized by conditions in which the native cattle do not show clinical manifestations of the disease, but introduced cattle suffer from an epizootic manifesting itself seasonally with varied intensity.

2. The degree of virulence exhibited and the species of tick acting as vectors have only an indirect significance as an indication of species of the parasite.

3. The facts relating to the development of Theileria in the tissues of infected animals and relation of this to developmental stages in the circulating blood are still far from clear.

4. The development cycle of Theileria in the red cells of the circulating blood of sick animals is described, and proof given that this is characterized by the formation of anaplasmatic forms developing into ring-shaped forms in T. annulata and T. dispar, and probably in all forms except, possibly, T. parva.

5. It is very desirable from the point of view of world economy that a special commission to study theileriasis in the different areas in which it occurs should be established on an international basis.

An Ischnopsyllus Westw., 1833, lately sent by Miss Kuei-Chen Li, National Kweiyang Medical College, China, differs considerably from all the known Ischnopsyllus and suggests that the species are as numerous in China as in Europe. Inclusive of Miss Li's specimens four eight-combed species from China are represented in the British Museum, all that have so far been described from that country. We are much indebted to Miss Li for the new species and to Mr Yin-ch'i Hsü for paratypes of two bat-fleas described by him

According to Carpenter (1993), the first problem for nutritional science, to identify the chemicals required in a diet to support human growth and maintenance, has been solved. Enough information has been amassed from the study of many populations to enable nutritionists to offer safe recommendations about daily intakes of energy and nutrients for all stages of the human life cycle (see reviews by Nesheim and by Solomons, this volume). Adoption of these recommendations would generally correct deficiency diseases and would reduce the incidence of health complications which are linked to excessive intakes of fat, sodium, alcohol and other substances. Carpenter also drew attention to malnutrition, the solution of which he believed to have become largely political and economic although the fact remains that very many people still do not receive or grow enough food. In the context of this volume, Carpenter's most interesting point was his view that our understanding of the complex relationship between nutrition and disease was still at an early stage.

An account is given of an investigation of the causes of error in estimating virus concentrations by the local lesion method. The irregularities were found to be due to:

(1) Variations in the response of (a) whole plants; (b) individual leaves.

(2) Variations in the volume of liquid used.

(3) Variations in the probability of the production of local lesions.

(4) Variations in the percentage of leaf hairs broken during the inoculation process.

An apparatus is described, the use of which reduces these irregularities to a minimum.

Observations on the egg-content of 78 counted populations of Metastrongylus apri showed that there was a positive correlation between population size and mean egg-content per female. In bilateral infections within one host, a significant tendency was shown for the larger of the two populations to outstrip the smaller in mean egg-content per female. There was no correlation between sex-ratio and mean egg-content. It is suggested that the effect of the host's defences against individual parasites is mitigated when large numbers of parasites are present.

A positive correlation was found between the sex-ratios of populations in left and right lungs, and there was a significant predilection of M. apri for the right lung.

I am indebted to Dr S. Peto, Microbiological Research Establishment, Porton, Wilts, for statistical advice, and to T. Wall and Sons Ltd., Atlas Road, London, N.W. 10, for access to abattoir material.