An investigation was made of the pathological, haematological and biochemical aspects of naturallyoccurring bovine fascioliasis in the Sudan. 228 animals infected with Fasdola gigantica and 25 non-infected controls were used in the study.

The infected cattle revealed emaciation, typical liver pathology, and, occasionally, lesions in the lung and the pancreas. Analysis of their sera also showed reduced albumin values, increased globulin concentrations and decreased albumin/globulin ratio, in addition to increased arginase activity. The serum iron concentration, on the other hand, was decreased, while the total iron binding capacity increased and the resultant iron saturation values reduced. Haematological findings in the infected animals included reduced erythrocyte counts, decreased haematocrjt values, increased mean corpuscular volumes, eosinophilia and decreased neutrophil, lymphocyte and monocytc counts.

Initial work on the fractionation of Schistosoma bovis adult worms is described. Both male and female worms were homogenized and sonicated before being passed through Sephadex G200. Five peaks were obtained with male fractionation (designated Ml to M5) and four with female (designated Fl to F4). Using the complement fixation test S. bovis antigen activity was detected primarily in peaks Ml and Fl. With the indirect haemagglutination and indirect haemagglutination inhibition tests S. bovis antigen activity was detected primarily in peaks Ml, M2, M3, Fl and F2.

Stammerinema suffodiax sp. n. is described from the dasyurid marsupial Antechinus stuartii. It differs from S. soricis, the only other member of the genus, in lacking lateral body spines, as vyell as in the spicules and characters of the anterior extremity. As well as red escribing Synfiimantus australiensis (Johnston and Mawson, 1952) now collected from the stomach of A. stuartii, a new capillariid, Capillaria rickardi from the stomach and two cestodes Hymenolepis aklei sp.n. and H. bradleyi sp.n. are described from the same host.

The susceptibility of 13 different B. forskalii strains from Zaire, Cameroun, Gabon, Senegal, Rhodesia and Tanzania and B. reticulatus wrighti Aden has been tested to infection with Schistosoma intercalatum from Cameroun. The most common prepatent period was 23–28 days.

B. forskalii from Zaire, Cameroun and Gabon were excellent intermediate hosts with infection rates varying from 59–0 to 97–4% and with very low death rates, 0-28-4%. The strains from Senegal and Rhodesia had infection rates from 500 to 58.4%. B. forskalii from Tanzania was refractory. 53.0% of the exposed B. reticulatus wrighti was infected. The total cercariae production per snail varied from 1000–11000. The duration of the infection varied from 8 to 174 days.

An indirect haemagglutination test has been developed for the detection of Schistosoma bovis antibody. Fresh, formalin and glutaraldehyde fixed sheep erythrocytes as well as fresh and formalin fixed human erythrocytes were tested. Tanned glutaraldehyde fixed sheep erythrocytes sensitized with an adult worm extract were the most sensitive and remained stable for at least 8 weeks at 4°C. With such cells 98% of a group of S. bovis infected cattle were positive while negative results were obtained from cattle infected with other helminths.

It was shown that ultra-violet radiation has a damaging effect on cercariae of Schistosoma mansoni and S. haematobium which are similarly influenced. Radiation of cercariae for intervals as short as 5–20 seconds markedly increased their mortality during penetration of host skin and inhibited migration of schistosomula in the lungs beyond days 3–4 post-infection. No mature adult worms were recovered from the liver and mesenteric veins of animals infected with irradiated cercariae. The practical significance of the cercaricidal property of ultra-violet radiation is discussed.

A survey was carried out of the levels of infection with Aspiculuris tetraptera and Syphacia obvelata in a wild house mouse population living in the Charles Clore Small Mammals Pavilion at the London Zoo in Regent's Park. The extent of infection with A. tetraptera is analysed according to the sex of the host. It is shown that the prevalence of infection was greater in male than in female mice and frequency distribution studies suggest that this is not only because fewer female mice become infected but also because females resist larvae more effectively than do males.

The fertility, mortality, and migration patterns of Heterakis gallinarum were studied in chickens with concomitant Parahistomonas wenrichi infections. H. gallinarum females were found to produce approximately 936 ova per day, when 50 days of age, and a total of 34,000 to 86,000 ova in a lifetime. There was no evidence of differential mortality between the sexes, nor of a preference for either the left or the right caecal organ of chickens. Both male and female worms are capable of migrating between caeca, and are especially prone to do so when in the absence of individuals of the opposite sex.

Studies were made of the fate of irradiated cercariae of Schistosoma mansoni, during their migration as schistosomula in the definitive host, by direct recovery of intact schistosomula from the skin and lungs and of adult worms from the liver of infected mice. Gamma radiation (6000 r) inhibited the migration and maturation of S. mansoni schistosomula to the adult stage. Penetration of irradiated cercariae into host skin proceeded normally and the first site of damage was in the lungs, but the majority of irradiated schistosomula were probably destroyed in the liver. The efiects of gamma radiation compared with those of ultra-violet radiation on cercariae of S. mansoni are discussed.

Experiments were conducted to assess the effect of sublethal concentrations of niclosamide on the infectivity of Schistosoma mansoni cercariae. Exposure of cercariae to 0.02 mg/1 and 0.05 mg/1 of niclosamide, respectively, for only two hours increased their mortality during penetration of mammalian host skin. The observed increase in mortality in the skin resulted in a consequent reduction of adult worm recovery from the liver and mesenteric veins of animals infected with the treated cercariae.

A description of the male and a redescription of the female of Philometra cylindracea, a parasite of yellow perch (Perca flavescens), are presented.

Philometra cylindracea has a one-year developmental cycle starting as infective larvae in June and becoming mature, larvigerous worms at the end of next June. Cyclops vernalis was found to be a suitable intermediate host under experimental conditions.

Spirura hipposidcrosi n.sp. from the stomach of Hipposideros ruber resembles S. diplocyphos but differs in the head structure, the shape and size of the spicules, the position of the vulva and the presence of a tuft of spines in the male tail. Spirura nycterisi n.sp. from Nycteris thebaica and Hipposideros ruber resembles S. spinicaudata but differs in the presence of a membrane round the posterior half of the left spicule, the presence of a tuft of spines at the tip of the male tail, the position of the vulva and the size of the eggs. A key to the African species of Spirura is given.

Observations have been made on the morphology of Bothriocephalus scorpii from littoral fishes in Britain, with particular reference to the reproductive system and the ultrastructure of the tegument. Two different kinds of microtriches, and ciliated sense organs, have been found. The shedding of proglottides by pseudoapolysis is described.

Microfilariae in whole uncentrifuged cat blood were transfused from infected to normal cats. The recipient cats were bled frequently and the life-span of the microfilariae in the peripheral circulation was determined. The life-span of microfilariae in different cats was very variable. Microfilariae were detected for 2–136 days after inoculation. In immunized cats microfilariae could not be detected 18 hours after inoculation. Any attempt to concentrate or clean the microfilariae caused them to disappear from the circulation more quickly.

Sporocysts capable of producing active miracidia were recovered from the upper branchial chamber of the snail species, Melania tuberculata and M.scabra. The non-ocellate miracidium was characterised by the presence of 22 epidermal plates in four tiers, an apical gland with four nuclei and two penetration glands. Sporocysts were of two types, one producing active miracidia and the other in which daughter sporocysts and miracidia were found. These sporocysts were characterised by the presence of bunches of circular muscles at intervals and also by the presence of a network of muscle fibres at the anterior and posterior one fifth regions. Development of the miracidia took place in compartments. Histochcmical tests were carried out as regards glycogen, protein, lipids and phosphomonoesterases.

Breinlia booliati exhibited nocturnal subperiodicity in its natural host, Rattus sabanus in contrast to experimentally infected laboratory-reared albino rats which showed irregular fluctuations of microfilariae throughout the 24 hour cycle. All the infected albino rats showed a prepatent period between 11–14 weeks postinoculation. Three patterns of microfilaraemia were discerned during the course of infection. 38/49 rats displayed a single peak, 4/49 displayed 2 peaks about 12–15 weeks apart and 7/49 showed a sustained high plateau-like pattern of microfilaraemia.

Cortisone had no effect on microfilarial levels when administered to rats near postpatcncy and some at postpatency.

A medicated diet containing 0.3% thiabendazole fed continuously to 26 mice for 7 days removed 9 out of 11 (82%) Hymenolepis nana, (one tapeworm remaining in each of two mice), 17 out of 17 (100%) Syphacia obvelata and 8 out of 8 (100%) Aspiculuris tetraptera infections. By contrast in 26 non-treated mice 9 out of 10 Hymenolepis, 17 out of 18 Syphacia and 8 out of 8 Aspiculuris infections persisted through the 7 day treatment period, and at post mortem examination 38 Hymenolepsis, 1,562 Syphacia and 4,911 Aspiculuris worms were recovered. In a second experiment 100% removal of 23 Hymenolepis and 20 Syphacia infections was obtained after 14 days medication of 38 mice. High activity against both roundyvorms and tapeworms of mice was thus obtained using one single drug. Some unexplained deaths amongst inbred strain C3H/Hef Nimr mice occurred within seven day's of the continuous medication.

Philometra kobuleji (Nematoda: Philometridae) is described as a new species from the abdominal cavity of a North American freshwater fish, Catostomits commersoni.

During a parasitological survey on stream fishes of Southern Ontario, males and females of a Philometra species were collected from white suckers, Catostomus commersoni (Laédpéde). This parasite differs from all known Philometra species recorded by Hoffman (1967) in North America.