Many basic data relating to the ecology of ticks are known, thanks mainly to the studies of Hunter, Bishopp and others on North American ticks.

From various parts of the world I have recently received a number of mites taken from bats, and the present paper gives descriptions and figures of five new species—one new species of the genus Ancystropus; two new species of the genus Spinturnix; one in the genus Hirstesia and the last in the genus Foliomyobia.

During the course of investigations into the distribution and seasonal activity of the tick, Ixodes ricinus L., in South Wales (Edwards & Arthur, 1945), a male tick was recovered which on examination was found to be a member of Ixodoidea, but which differed from the normal male of I. ricinus L. It was recovered from Margam Moors (Glamorgan, South Wales) by one of the writers (D.R.A.) in 1945, whilst dragging a blanket over rough vegetation, a method previously employed by MacLeod (1932) for the recovery of ticks from grassland. This is the only specimen of its kind which has been found, despite the examination of several thousands of males during the past three years. It has therefore been considered desirable to place on record a description of the form. When placed in a tube containing ten unfed females of I. ricinus, no mating occurred. Under similar conditions a typical male of this species mated with one unfed female within 7 minutes of its introduction.

The genus and species of Lygaeidae described and figured herein was obtained with several others from a squirrel's nest at Kodera, S. Nyanza Province, Kenya, East Africa, by Dr Garnham, Professor of Medical Protozoology at the London School of Hygiene and Tropical Medicine.

The interaction between Heligmosomoides polygyrus superantigen and human peripheral blood mononuclear cells (PBMC) was evaluated. Parasite homogenate and excretory–secretory proteins from both L4 larvae and adult worms were examined for their ability to stimulate, and be presented by, human cells. Proliferation assays using PBMC from 3 human volunteers indicated that naïve cells were stimulated by H. polygyrus superantigen. Antigen presenting cells (APC) from a number of human donors were able to successfully present H. polygyrus superantigen to mouse T cell hybridomas. However, this ability varied according to the source of the superantigen, and human APC, in contrast to APC from mice, could only present the superantigen contained within parasite homogenate. Also, in contrast to the situation with mice, human APC could present H. polygyrus superantigen to stimulate mouse T cells expressing not only TCR Vβ8.1, but also TCR Vβ7. Therefore, H. polygyrus superantigen can successfully stimulate, and be presented by, human PBMC of different MHC haplotypes, although the cellular mechanisms appear to be different from those observed in the mouse.

While examining the strongyles of the fourth stomach of an ewe belonging to the Cambridge University Farm, which had been slaughtered for post-mortem examination, numerous male and female Ostertagia circumcincta (Strongylus cervicornis of MacFadyean) were found. A few specimens of Haemonchus contortus were also present.

In my “Revision of the Genus Stilesia” I had to leave several points in the anatomy of Stilesia globipunctata (Riv.) undecided, as the material I had of the worm was too macerated to allow of any definite conclusions. At the same time I pointed out, that the topography of the male canals as described by Stiles and Hassall disagreed with the conditions obtaining in Stilesia hepatica Wolffhügel, in other respects a very closely related species. The necessity for a re-examination of Stilesia globipunctata (Riv.) in order to decide whether the differences really exist, or whether they were supposed to do so, on account of the material examined by Stiles being rather macerated (loc. cit. p. 74), was all the greater as Stilesia globipunctata (Riv.) is the type species of the genus Stilesia. Through the kindness of Mr Littlewood, Chief Inspector of the Veterinary Department, I was able to obtain living examples of Stilesia globipunctata (Riv.) at the Cairo abattoir on Jan. 27, 1912. These worms have been fixed with Zeuker's solution, hardened and cut.

Agrippina bona, a gregarine parasitic in the gut of the larva of the rat-flea Ceratophyllus fasciatus, was first described by Strickland in 1912. His account of the sporulation of the gregarine was so curious that a more detailed investigation has been undertaken, which has given rise to the present paper. The work has been done in the Quick Laboratory, under Professor Nuttall, to whom I wish to express my thanks for the interest he has taken in my researches, and for his constant encouragement.

The somatic muscle of Ascaris suum is principally under the excitatory control of neuromuscular junction transmitter, acetylcholine (ACh). However, it has recently been shown that neuropeptides also play an important role in the motor-nervous system and one of these, AF3 (AVPGVLRFamide), also contracts muscle. The events which trigger contraction to ACh and AF3 would appear to be different, with ACh activating a nicotinic acetylcholine receptor whilst the response to AF3 is most likely to involve a G-protein coupled receptor negatively coupled to adenylate cyclase. In order to further elucidate differences in the cellular signalling pathways through which ACh and AF3 elicit muscle contraction, we investigated the actions of protein kinase C inhibitors, tamoxifen and chelerythrine, on the dorsal somatic muscle strip of A. suum. Contractions in response to 1 μM AF3 were potentiated by 17% in the presence of 10 μM tamoxifen (P<0·05; n=8); however, contractions in response to 10 μM ACh were markedly inhibited (tamoxifen IC50 44±18 μM; n=6). Tamoxifen also blocked muscle cell depolarizations to 5 μM ACh (IC50 4±1 μM; n=6) and 1 μM levamisole (IC50 14±6 μM; n=4). This was unlikely to be a non-specific effect on the membrane as hyperpolarizations to 10 μM GABA were unaffected (93% of control with 10 μM tamoxifen; n=6; P>0·05). However, another inhibitor of mammalian protein kinase C, chelerythrine, did not affect the response either to ACh or AF3 (n=6).

The present study was performed on antigen-presenting cells (APCs) of Theileria annulata transformed dendritic cells (TaDCs) and monocyte-derived dendritic cells (MoDCs) to compare differences in antigen presentation and stimulation of T lymphocyte proliferation. Antigen presentation for T lymphocyte proliferation was analysed by flow cytometry. Additionally, the level of mRNA transcription of small GTPases of the Rab family expressed in the TaDC cell line was analysed by quantitative real-time polymerase chain reaction (Q-RT-PCR). The endocytosis rate of TaDCs was significantly (P < 0.01) lower than in MoDCs. In contrast, when T lymphocytes were co-cultured with TaDC-APCs T cell proliferation was similar, while co-culture with MoDC-APC stimulated proliferation of CD4+ cells to a greater degree than CD8+ cells. However, the efficacy of TaDC-APCs to stimulate T lymphocytes dropped as the number of passages of TaDC-APC increased. Likewise, the transcription level of Rab family genes also significantly (P > 0.001) declined with progressive passages (>50) of the TaDC cell line. We conclude that initially the TaDC cell line efficiently presents antigen to stimulate T lymphocyte proliferation to produce a cellular immune response against the presented antigen.

The monogenean (platyhelminth) skin parasite Entobdella soleae from the common sole (Solea solea) lays tetrahedral eggs. One of the 4 corners of the tetrahedron is a detachable operculum which is bonded to the rest of the egg-shell by cement. Most of this cement layer, beginning at the inner surface of the shell and running through almost to the outer surface (a distance of about 2 μm), is more or less uniform in thickness (30–38 nm), or tapers slightly. About 345 nm from the outer surface the cement layer narrows abruptly to about 10 nm. The cement is exposed on the inner surface of the shell, but in most eggs a layer of shell about 10 nm thick covers the narrow outer region of the cement layer. When experimentally perforated eggs were incubated with trypsin, the wide inner layer of cement was digested, but the narrow outer region initially remained intact. These observations are discussed in relation to the following (1) survival of the eggs during embryonic development, (2) hatching, (3) the ‘hinge’ often connecting the operculum to the empty egg-shell, (4) the rapid hatching that occurs in some other monogeneans.

We present a mathematical model which is used to interpret the dynamics of the immunological response of a mouse host to infection with the filarial worm Onchocerca lienalis. The model mimics changes in worm burden over time post-infection and after reinfection and its behaviour provides a good description of experimental results. Measured production of T-cells and eosinophils is also compared with the predictions of the model. Our results show that the immune response mechanism proposed on the basis of experimental results, involving CD4+ T-cells and eosinophil destruction of the parasite, is supported by the insights gained from the mathematical model. Also, using the parameters estimated to describe the primary infection dynamics, the degree of acquired immunity to secondary infection is also well described by the model. Our analysis highlights the importance of obtaining quantitative measures of the many rate parameters involved in even the simplest interpretations of immunological responses to parasitic infection.