The tissue reactions in mice, experimentally infected with normal and irradiated cercariae of S. incognitum were studied. The lesions observed in the skin, liver, lungs and the intestine of mice infected with normal cercariae are briefly described, and compared with those observed with cercariae irradiated at 3000 r of gamma rays. In general, the reactions in mice exposed to normal cercariae were more intense than in those infected with irradiated cercariae. The severity of the reactions appeared largely due to the deposition of eggs in the tissues of the mice infected with normal cercariae. The experimental evidence suggested that most of the flukes from the irradiated cercariae are destroyed in the liver by tissue reaction.

Various stages of Angiostrongylus cantonensis recovered from the brain of experimentally infected mice were transplanted intracranially into rats. Third and fourth-stage worms recovered 2–7 days postinfection were able to develop normally after transplantation into recipient rats. The fifth-stage worm obtained 14–15 days postinfection would enter the brain tissue of rats but died shortly afterwards. However, the same stage of worms recovered from rats, after a similar transplantation, were found to develop normally in the recipient animal. Young fifth-stage worms, from the subarachnoid space of rats, which were ready for the pulmonary migration were also transplanted into rabbits but the worms failed to reach the lungs. In the control rat-to-rat transplantation, the worms successfully completed the pulmonary migration. The morphogenesis and initial growth rate of A. cantonensis were similar in both mice and rats but in the former host the worms started to grow at a markedly slower rate after the last moult and gradually degenerated.

Moaciria sphenomorphi n. sp. is described from the skink Sphenomorphus gracilipes, Moaciria butleri n. sp. from the elapid snake Pseudechis australis (both from Western Australia), and Moaciria etnae n. sp. from the python Liasis childreni from Queensland. These species differ from one another and from M. alvarengai and M. icosiensis principally in the number and disposition of body and caudal papillae, and from M. freitasi in possessing caudal alae. M. butleri and M. etnae also differ from the other species in possessing a conspicuous three-pointed internal lip tooth, and all three new species possess a small median papilla within the posterior rim of the precloacal sucker.

A new flotation technique for the extraction of Toxocara eggs from soil has been devised. It has a fairly high recovery efficiency for Toxocara eggs, can be used for replicated quantitative experiments, and may also be used for recovery of other ascarid eggs from soil.

Out of a total of 282 soil samples obtained from public areas, 58 samples contained Toxocara spp. eggs. This gave an overall prevalence of 20.6%. Highway rest areas were contaminated and childrens sand boxes had the highest percentage of recovery of all.

The prevalence of Capillaria hepatica (Bancroft, 1893) infection in a total of 2324 rats trapped from 25 localities in West Malaysia was 15.5%. Infection rates in males (16.0%) and females (15.1%) are similar. A significantly higher percentage of adults (18.1%) than young (7.7%) was infected. Capillaria hepatica infection rates amoung urban (0.7%) and jungle (0.0%) rats was very low as compared to field rats (17.7%) trapped from agricultural areas such as oil palm estates and rice growing areas.

Prevalence of C. hepatica infection in rats is not evenly distributed throughout West Malaysia. There seem to be localised foci of infection. In some areas as many as 77.8% of the adult rats are found to be infected while in other areas the same species of rats are found free of infection.

Progamotaenia gynandrolinearis sp. nov. is described from the small intestine of Lagorchestes conspicillatus Gould, 1842 from Barrow I., Western Australia. It is distinguished from other species by the small number of testes arranged in a single transverse row. Progamotaenia lagorchestis (Lewis, 1914) is redescribed. The name Progamotaenia thylogale sp. nov. is proposed for a second species described previously under the name P. lagorchestis. Progamotaenia zschokkei (Janicki, 1905), Progamotaenia festiva (Rudolphi, 1819) and Progamotaenia villosa (Lewis, 1914) were also found in L. conspicillatus.

Neodiplostomum (Conodiplostomum) ramachandrani Betterton, 1976 has been reported from four species of rodent hosts: Echinosorex gymnurus (Raffles): Rattus whiteheadi (Thos); R. muelleri (Jentink) and Callosciurus notatus (Boddaert). A comparison of trematodes recovered from these hosts revealed patterns of host-induced morphological variation taking place. Because N. (Conodiplostomum) ramachandrani shows little generic difference from Fibricola intermedius (Pearson, 1959) Sudarikov, 1960 it is transferred to the genus Fibricola and is now designated Fibricola ramachadrani (Betterton, 1976) Palmieri, Krishnasamy and Sullivan.

The effect of graded doses of diethylcarbamazine on the concentration of microfilariae in the hydrocoele fluid, urine and skin of patients suffering from onchocerciasis was studied. The results showed that a significant number of microfilariae migrated into hydrocoele fluid and urine immediately after the drug was given and thereafter returned to pre-treatment levels rather more quickly in the former than the latter. The increase was found to be roughly directly proportional to the intensity of infection in the skin. By contrast the skin concentration of microfilariae fell sharply after treatment and remained significantly lower than pre-treatment levels for over four weeks. The potential use to which these observations could be put with respect to clinical screening of drugs in onchocerciasis is discussed.