MUCH work has already been carried out on the treatment of mice infected with schistosomes. It has been observed that the worms which normally inhabit the mesenteric veins of animals infected with Schistosoma mansoni are forced to migrate to the liver after treatment with active schistosomicidal drugs1–6. This hepatic shift has usually been observed after a full course of treatment, and where the course had been inadequate, relapses were found to occur owing to the re-migration of the worms back to the mesenteric veins. Standen6observed a hepatic shift as early as one day following two oral doses of 42 mgm./ kgm. sodium antimonyl III gluconate, but after 7 days the worms were completely restored to their normal distribution in the hepatic portal system. In the work reported here we followed up the effect of a single dose of tartar emetic on the worm migration to show that the hepatic shift actually occurs much earlier than had been previously expected

The body weights of 7 to 9 month-old White Leghorn males were observed by Lamoreux (1943) to be significantly greater when light was restricted to less than 9 hours per day. Siegel et al. (1961) reported significantly heavier body weights and better feed conversion in White Leghorn pullets at 8 weeks of age when restricting light to 6 hours per day compared to 14 hours of light per day. In a study with broiler chickens, Moore (1957) found that faster growth was obtained up to 3 or 4 weeks of age with continuous light although feed efficiency was slightly better with less light throughout the growing period. A series of experiments reported by Shutze et al. (1960) indicated that birds exposed to continuous light were superior in body weight gain to those on the other light regimes with the exception of one experiment in which chick growth response to 2 . . .