The Indian gerbil, Tatera indica indica, was collected in the arid western Rajasthan at Bikaner during the first weeks of July, August and September 1968. From sixty gerbils a large number of nematodes belonging to the genera Streptopharagus Blanc, 1912, Rictularia Froelich, 1802 and Trichuris Roederer, 1761, together with a few cestodes, were recovered from the stomach and intestine. The Streptopharagus sp. described below, vastly outnumbered the other worms and appears to be a new species.

An echinostome obtained from the kidney of the North American White Pelican, Pelecanus erythrorhynchos is described as a new species, Allechinostomum renale.

Allechinostomum is regarded as a valid genus.

A differential key to the four-known species of the genus is appended.

The karyotypes of the two amphistomes Calicophoron microbothrium Fischoeder, 1901 and Carmyerius gregarius (Looss, 1896), Stiles & Goldberger, 1910 from Egyptian ruminants were studied using the air drying technique. The two species have similar number of chromosomes (n = 9), but differ in chromosome morphology. All the chromosomes of C. microbothrium are subtelocentric, except the first and the fifth are metacentric, whereas the chromosomes of C. gregarius are submetacentric, subtelocentric and acrocentric. Some cells in the two species showed tetraploidy. The results are discussed in terms of the phylogenetic relationship of different amphistomes.

Ultrastructural studies were undertaken on a discrete peri-vulval area of cuticular modification in the parasitic female of Strongyloides cebus. Cilium-like arrangements of microtubules were observed which suggested that this region was sensory in nature. The possible function of this is discussed.

Two specimens of this fluke were collected from the nictitating membrane of the Steppe Eagle, Aquila nipalensis Hudson, shot near the lake Chinhut, about 5 miles from Lucknow, U.P.

The body.(Fig. 1) is aspinose, flattened and clavate with a narrow anterior and a broadly rounded posterior end. It measures 4·5–5·9 mm. in length and 1·5–1·8 mm. in maximum width in the middle region. The oral sucker is terminal measuring 0·33–0·36 mm. X 0·47–0·49 mm. The ventral sucker is larger than the oral sucker, situated at the level of the division of. the anterior and middle-thirds of the body, and about 1·14 mm. from the anterior extremity. It measures 0·56–0·61 mm. X 0·52–0·54 mm.

The protein composition of various developmental stages of Dipetalonema viteae was analysed on polyacrylamide slab gels in the presence of sodium-dodecylsulphate. When the total proteins of adult male and female parasites, microfilariae, eggs, and third-stage larvae were compared, apparent qualitative similarities between mature and immature filariae were observed. However, several stage specific components were also identified.

Pyridoxine (vitamin B6) deficiency was induced in cotton rats which were then infected with the filarial parasite Litomosoides carinii. Embryogenesis was assessed microscopically in worms taken from pyridoxine deficient cotton rats and from various categories of control animals. Embryogenesis was retarded in worms from pyridoxine deficient hosts and more abnormal embryos were present in such worms than in those from control animals.

Twenty-eight adult specimens of 2 new species, Aphelcnchoides appendurus and A. montanus, were collected from the rhizoids of moss adhering to the bark of pine trees in the Mussoorie Hills, at an altitude of 7,500 feet above sea level, in Uttar Pradesh, India.

The 2 new species, which belong to the “parietinus” group of the genus Aphelenchoides Fischer, 1894, are described and illustrated.

It is well known that the first two larval stages in the life cycle of nematodes belonging to the superfamily Strongloidea, have a freeliving existence. During this time, the larva which hatches from the egg feeds actively, undergoes two moults and grows considerably before reaching the infective stage, when it is ready to invade a definitive host. Under natural conditions this external development takes place in the faeces, which have been deposited by the infected host on ground likely to be contaminated with various bacteria.

1. Ten species of Capillaria are recorded from eight species of British birds. C. blomei from the pheasant and partridge and C. exilis from the rook are new host records.

2. The identity of C. reseda and the systematics of C. blotnei, C. bursata and C. caudinflata are discussed in the light of observations made upon material in the collection.

Neodiplostomum (Conodiplostomum) ramachandrani sp. n. is described from Rattus muelleri in Kepong, Selangor, Malaysia. It is characterised by having symmetrical dumbell-shaped testes, and vitellaria as a single ventral band in the hindbody. The taxonomic relations ofNeodiplostomum, Conodiplostomum and Fibricola are discussed and possible significance of the fluke as an ecological indicator noted.

Cystic echinococcosis caused by Echinococcus granulosus sensu lato is one of the most important helminth zoonoses in the world; it affects both humans and livestock. The disease is endemic in Argentina and highly endemic in the province of Neuquén. Considerable genetic and phenotypic variation has been demonstrated in E. granulosus, and ten different genotypes (G1–G10) have been identified using molecular tools. Echinococcus granulosus sensu lato may be considered a species complex, comprised of E. granulosus sensu stricto (G1–G3), E. equinus (G4), E. ortleppi (G5) and E. canadensis (G6–G10). In endemic areas, the characterization of cystic echinococcosis molecular epidemiology is important in order to apply adequate control strategies. A cut-off value for larval large hook total length to distinguish E. granulosus sensu stricto isolates from those produced by other species of the complex was defined for the first time. Overall, 1780 larval hooks of 36 isolates obtained from sheep (n= 11, G1), goats (n= 10, G6), cattle (n= 5, G6) and pigs (n= 10, G7) were analysed. Validation against molecular genotyping as gold standard was carried out using the receiver operating characteristic (ROC) curve analysis. The optimum cut-off value was defined as 26.5 μm. The proposed method showed high sensitivity (97.8%) and specificity (91.1%). Since in most endemic regions the molecular epidemiology of echinococcosis includes the coexistence of the widely distributed E. granulosus sensu stricto G1 strain and other species of the complex, this technique could be useful as a quick and economical tool for epidemiological and surveillance field studies, when fertile cysts are present.

The fish populations of three reservoirs and one river in the Northamptonshire area were examined over a four-year period for the plerocercoid of Ligula iniestinalis. The infection was observed in two of the three reservoirs but was not found in the river Nene. The reservoir which had no infection contained no cyprinids.

Infected hosts progressively decrease egg output during the chronic phase of Schistosoma mansoni infection. Ageing may be a factor that results in a progressive decrease in the ability to reproduce. This study was performed to gain insight into the effects of ageing on adult schistosomes, using confocal laser scanning microscopy. Adult worms were recovered from experimentally infected Nectomys squamipes (water rat). Viable eggs were voided in the faeces for 65 weeks and, thereafter, only unviable eggs were eliminated. The rat died after 70 weeks in captivity. Recovered worms (six males and one female) were prepared for confocal microscopy and images were obtained with an LSM 510–ZETA laser confocal microscope. The overall morphology of the adult worms (suckers and tegument) and reproductive organs were the focus of this work. The suckers, ovary, vitellaria and oocytes appeared to be apparently normal. The ootype was formed by flattened cells and unclear nuclei, suggesting that the mechanism for eggshell production by the ootype during organogenesis might have been impaired. Testicular lobes showed empty areas around the germinative cells. Male adult worms showed flaccid musculature of the dorsal surface. Taken together, the present results provided several indications of infertility in older male and female schistosomes.

The results obtained in the tests described above are summarized in the following table :—

Matricaria matricarioides (Less.) Porter, self-sown in one of the inoculated pots, is an addition to the known weed hosts of narcissus races of D. dipsaci and a new host record for the species.

Seinhorst (1952) has emphasized the need for caution in interpreting the results of host tests with D. dipsaci. Exposure to heavy infestations will often result in invasion and local necrosis of the tissues of plants which are not true hosts of the race concerned. Seedlings may easily be killed outright in this way. The present tests lead to similar conclusions as shown, for example, by the results obtained with red clover and oat seedlings. Even deposition of eggs in the tissues cannot be taken as evidence that the eelworms have established themselves. It is considered, however, that a plant may be regarded as a true host when it is clear that the eelworms are breeding freely in the tissues, i.e. when eelworms in all stages of development are present with numerous eggs, and when infestation is able to persist during the normal life of the plant. With bulbous plants, the establishment of an infestation in the new bulbs after the leaves and flowers had died down was taken as evidence that the plant was a true host. The typical effects of D. dipsaci on the tissues of its hosts, e.g. hypertrophy of parenchyma tissues, enlargement and loosening of the cells and dry, mealy rotting, are also useful criteria, but some of these effects may be produced occasionally after invasion of non-hosts, as was found in a few of the inoculated clover seedlings.

This article communicates the relative quantification of five isoforms of antigen B (AgB) of Echinococcus granulosus. Relative expression of the AgB was quantified in active and inactive cysts. Cysts with germinal membrane, clear cyst fluid and protoscoleces showed uniform expression of the five isoforms and were utilized as control. Relative expression of AgB1 was the highest in cysts, where calcification has initiated. AgB2 and AgB4 were expressed more in fertile cysts irrespective of the condition of germinal membrane. The lowest expression of AgB3 was seen in calcified cysts. The relative expression of AgB5 could not be correlated with respect to the condition of the cyst because AgB5 is typically expressed by the adult stage of the parasite.

The formation of nurse cells in host muscle cells during Trichinella spiralis infection is a key step in the infective mechanism. Collagen trimerization is set up via disulphide bond formation, catalysed by protein disulphide isomerase (PDI). In T. spiralis, some PDI family members have been identified but no localization is described and no antibodies specific for T. spiralis PDIs are available. In this work, computational approaches were used to search for non-described PDIs in the T. spiralis genome database and to check the cross-reactivity of commercial anti-human antibodies with T. spiralis orthologues. In addition to a previously described PDI (PDIA2), endoplasmic reticulum protein (ERp57/PDIA3), ERp72/PDIA4, and the molecular chaperones calreticulin (CRT), calnexin (CNX) and immunoglobulin-binding protein/glucose-regulated protein (BIP/GRP78), we identified orthologues of the human thioredoxin-related-transmembrane proteins (TMX1, TMX2 and TMX3) in the genome protein database, as well as ERp44 (PDIA10) and endoplasmic reticulum disulphide reductase (ERdj5/PDIA19). Immunocytochemical staining of paraffin sections of muscle infected by T. spiralis enabled us to localize some orthologues of the human PDIs (PDIA3 and TMX1) and the chaperone GRP78. A theoretical three-dimensional model for T. spiralis PDIA3 was constructed. The localization and characteristics of the predicted linear B-cell epitopes and amino acid sequence of the immunogens used for commercial production of anti-human PDIA3 antibodies validated the use of these antibodies for the immunolocalization of T. spiralis PDIA3 orthologues. These results suggest that further study of the role of the PDIs and chaperones during nurse cell formation is desirable.

Preliminary investigations on the problem of affording protection to the potato plant growing in soil infested with cysts of Heterodera schachtii, were carried out by Hurst & Triffitt (1935, i, ii, 1937). In these experiments promising results were obtained by the application of calcium cyanamide or of ferric oxide to the soil, and trials with these chemicals were designed on a larger'scale. A small field experiment (Hurst & Franklin, 1937) was carried out in Lincolnshire during 1936, using dressings of 30 cwt. per acre of calcium cyanamide and 12 cwt. per acre of ferric oxide. On the cyanamide plots an increased yield of potatoes was accompanied by a relatively small increase in the cyst population of the soil. With ferric oxide the results were not significantly different from those on the untreated control plots.