Gavage administration of cambendazole at 50 mg/kg was found to eliminate a 7 hour Trichinella spiralis infection in mice. Cambendazole was also found to be highly active against the muscle phase of trichinosis. Partial activity was also indicated against migratory larvae and adult worms. Cambendazole appears to have a sterilising effect on adult T. spiralis. It is postulated that cambendazole has potential therapeutic value.

The variations in the oxygen uptake, reduced weight, metabolic rate and the number of contained, fully formed, healthy, autolysed or dead metacercariae, recorded during starvation in sea water, in vitro, suggest that first mainly stored carbohydrates, then mainly lipids and, in the final stages of starvation, mainly proteins are broken down and metabolised, by the sporocysts of Microphallus pygmaeus.

The trematodes of this report were killed in hot water, transferred immediately to Lavdowsky's FAA fixative for 24 hours, and then stored in 70% alcohol plus 2% glycerine. Whole mounts were stained in Mayer's carmalum and mounted in permount. Specimens have been deposited in the U.S. National Museum Helminthological Collection as indicated. All measurements are in microns (ftm).

A rapid technique for the assessment of a larval population on herbage is presented. Factors influencing the reliability of this technique and the problems encountered whilst trying to estimate efficiency of recovery rate are discussed.

A new species of the genus Euparadistomum is described from the gall bladder of the domestic cat on Gemo Island, Papua. The incidence of the parasite is extremely low in the Port Moresby area, being recorded from only 1·6% of cats examined. E. pearsoni is the second species recovered from the domestic cat. A revised key to the genus is provided.

1. Helerakis gallinarum recovered from chickens, and apparently having lived exclusively or predominantly in chickens for several years, thrived better in chickens than in turkeys, when several hundred embryonated eggs were given in a single feeding.

2. Use of a smaller inoculum reduced the difference in the worm's performance in its traditional host and the new host species.

3. Performance in both species of host was the same following the feeding of small numbers of eggs from worms grown 1 generation in turkeys.