A male and a female of a species of Syngamus were found in copula in the small intestine, about 1 in. from the gizzard, of a fieldfare (Turdus pilaris) which had been shot accidentally. The nematodes were well preserved and were undamaged. Eighty-four small tapeworms, of two different genera, were also present in the intestine. Neither the tapeworms nor the nematodes were attached to the intestinal wall.

1. A new species of tick, I. theileri from South Africa, is described. Hitherto it has been collected only from birds.

2. Existing descriptions of I. daveyi Nuttall 1913 and I. brunneus Koch 1844 are amplified, and the synonymy of I. frontalis (Panzer, 1795) discussed.

3. Diagnostic characters, whereby I. daveyi, I. brunneus, I. frontalis and I. theileri may be separated, are tabulated.

Some account is given in this paper of certain nematodes obtained by Prof. G. E. Gates from the coelomic cavities of various species of earthworms from South India, Assam and Singapore. The material was kindly submitted to the writer by Prof. Gates in 1936, 1937 and 1939. Of the forms included in it several were represented by specimens insufficient or unsatisfactory for adequate description, and it has seemed advisable to deal only with those species of which a reasonably full account can be given. Of these there are seven, all of which are thought to be new. Four of them can be assigned to a known genus, Synoecnema de Magalhães, 1905; the other three probably represent as many new genera.

In an earlier paper (Nuttall, Fantham and Porter, 1909, Parasitology vol II. pp. 325—340), we recorded our observations on living Theileria parva as seen in the peripheral blood of two cows which succumbed to East Coast Fever1. We now propose to describe our studies upon the parasite in stained preparations made from the animals' blood during the course of the disease and from their organs shortly after death. We shall confine our attention to the types of parasites encountered within red blood corpuscles or to corresponding types which may be occasionally encountered free in the plasma. The subject of “Koch's blue bodies” will receive attention at a later date.

Acetylcholine (ACh) is one of an array of neurotransmitters used by invertebrates and, analogous to vertebrate nervous systems, acetylcholinesterase (AChE) regulates synaptic levels of this transmitter. Similar to other invertebrates, nematodes possess several AChE genes. This is in contrast to vertebrates, which have a single AChE gene, transcripts of which are alternatively spliced to produce different types of the enzyme which vary at their C-termini. Parasitic nematodes have a repertoire of AChE genes which include those encoding neuromuscular AChEs and those genes which code for secreted AChEs. The latter proteins exist as soluble monomers released by the parasite during infection and these AChE are distinct from those enzymes which the nematodes use for synaptic transmission in their neuromuscular system. Thus far, Dictyocaulus viviparus is the only animal-parasitic nematode for which distinct genes that encode both neuromuscular and secreted AChEs have been defined. Here, we describe the isolation and characterization of a cDNA encoding a putative neuromuscular AChE from D. viviparus which contains a tryptophan amphiphilic tetramerization (WAT) domain at its C-terminus analogous to the common ‘tailed’ AChE form found in the neuromuscular systems of vertebrates and in the ACE-1 AChE from Caenorhabditis elegans. This enzyme differs from the previously isolated, D. viviparus neuromuscular AChE (Dv-ACE-2), which is a glycosylphosphatidylinositol-anchored variant analogous to vertebrate ‘hydrophobic’ AChE.

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.

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.

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.

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.

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.

1. Adult S. mansoni worms were extracted in Coca's solution at various temperatures by different methods. The most potent antigen was obtained by extracting a worm suspension, diluted 1:500, at 37° C. for 1 hr., with vigorous shaking at 10 min. intervals, followed by 23 hr. at 28° C. Second extraction of worm samples gave highly active material and third extractions also contained antigen.

2. Complement-fixation tests, performed with the sera of twenty-five patients with chronic bilharziasis and twenty-five healthy subjects showed that the most specific results were obtained with either the first two extracts of worms, suspended in 100 parts of Coca's solution, and extracted for 1 hr. at 37° C. and 23 hr. at 28° C., or with the first extract of worms, suspended in 500 parts and extracted in the same manner.

3. Samples of an extract in Coca's solution were preserved for 170 days by different methods, and their activity was tested at approximately monthly intervals. The antigen, with or without the addition of 0·1% cysteine, retained its titre for 1 month, when kept in the refrigerator. Freezing, or lyophilization of the extract caused a rapid drop in titre.

4. Titration of extracts of lyophilized worms, from freshly opened ampoules, showed that a constant titre was retained for 3½ months followed by a slight drop after 5–6 months. The worm powder retained its antigenic potency when kept, thoroughly desiccated, in the refrigerator for 4 months, but lost it in 40 days when partial rehydration occurred.

Prophryxus, a new genus of hemiarthrinid bopyrid from Kenya, is described. The only species, P. globicaudatus, is parasitic upon the shrimp Coralliocaris graminea (Dana). Prophryxus is considered to be most closely related to the genus Hemiarthrus Giard & Bonnier, from which it differs in the morphology of the abdominal appendages. It is most remarkable for the presence of a sucker-like organ on the dorsum of the cephalon, a feature unique in the Bopyridae.

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.

In a previous paper, Nuttall and Graham-Smith (Parasitology, 1908, vol. i. p. 134) described the appearances presented by P. bovis in stained films, and showed that they agreed with those of P. canis and P. pitheci with regard to the presence of the “budding” or multiplication forms. The multiplication of P. bovis in fresh blood films remained, however, to be described.

1. The mosquito fauna of the Cambridge district, which includes a large stretch of cultivated fenland, is compared with that of the “natural” fen at Wicken and also with that of other districts.

2. The ecology of the various species is discussed and the conclusion is reached that the main factor determining why different species are found in different types of habitat is the time of year at which the female lays her eggs, and whether she lays them on damp ground or standing water.

This paper demonstrates that the activities of glycogen phosphorylase (GP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are reduced in adult worms of the filarial nematode Litomosoides carinii recovered from pyri-doxine-deficient cotton rats when compared to worms recovered from pyridoxine-sufficient controls. GP, ALT and AST activities were determined in adult worms L. carinii recovered from cotton rat hosts over a 20-week experimental period. Activities of GP, ALT and AST in the parasite showed a direct correlation with the dietary pyridoxine intake of their host. Throughout the experiment, enzyme activities were significantly lower (P < 0·001) in worms from rats fed a pyridoxine-free diet ad libitum that in worms from rats fed either a stock colony diet, a pyridoxine-free diet ad libitum with daily supplementation of 100 μg pyridoxine or limited amounts of pyridoxine-free diet with daily supplementation of 100 μg pyridoxine. The lower than normal activity of GP, ALT, AST and other enzymes dependent on the biologically active derivative of pyridoxine, the coenzyme pyridoxal-5-phosphate (PLP), interferes with the protein, carbohydrate and lipid metabolism of L. carinii and may in part cause the reduced establishment, development and growth of the parasite in pyridoxine-deficient hosts.

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.

During the handling of about 10,000 ticks in the course of insecticidal tests many abnormalities of the legs were encountered. Most of the cases were deficiencies due to the partial regeneration of a leg damaged in the previous nymphal stage. Two cases of special interest were not deficiencies, but exhibited supernumerary segments of leg.