SUMMARY. The metabolism of Tritrichomonas foetus (strain, BP‐1) and trichomonads from the nasal cavity and cecum of swine was studied manometrically under similar experimental conditions. At pH 6.4, quantitative and qualitative differences were observed. The cecal (probably T. suis) and nasal trichomonad used glucose, galactose, fructose, mannose, lactose, sucrose, raffinose, and trehalose. T. foetus used all except lactose and raffinose. All three were inhibited by iodoacetate and arsenite. T. foetus and the nasal form were significantly inhibited by fluoride and 8‐hydroxyquinoline, whereas the cecal trichomonad was not. At varied pH, all failed to oxidize Krebs' cycle intermediates. The amounts of oxygen consumed by T. foetus and the nasal trichomonad in the presence of lactate and pyruvate were at levels similar to those with disaccharides; the cecal trichomonad was indifferent toward both substances. Anaerobically, lactate and pyruvate increased the evolution of gas by all three trichomonads. Aerobic acid formation was demonstrated for all three forms. Anaerobically, metabolic CO2 and gas(es) that were not absorbed by KOH were evolved by all three. Pure oxygen was inhibitory to glucose utilization and stimulatory to the endogenous respiration of all trichomonads; the nasal form was affected the least. The writer believes that the cecal trichomonad is different from T. foetus and the nasal trichomonad of swine. The relationship between the nasal trichomonad and T. foetus remains in doubt.

SYNOPSIS. Inhibitors, acid production, and substrate utilization by 4 strains of Tritrichmonas foetus (BP‐3, BP‐4, A‐1, and A‐2) were studied manometrically. All used glucose, galactose, mannose, fructose, sucrose, maltose, trehalose, glycogen, starch, lactate, and pyruvate. Strain A‐1, with the highest aerobic and anaerobic endogenous rates, used these substrates less than did the others. Strain BP‐3 did not use lactose; strains BP‐4 and A‐2 did not use raffinose aerobically and only slightly anaerobically; strain A‐1 used both nearly as well as maltose and sucrose. All were strongly inhibited by iodoacetate and, if tested in the presence of glucose, aerobically or anaerobically, by fluoride, arsenite, hydroxylamine, and 8‐hydroxyquinoline. Aerobically, 2,4‐dinitrophenol produced stimulation which was greater in the presence of glucose; anaerobically, it produced inhibition which was, in some cases, comparable to the effects produced by the other inhibitors. Fluoride, arsenite, azide, and hydroxylamine, although producing insignificant inhibitory effects on endogenous O2 consumption, reduced and, in some cases, abolished motility of all strains. All 4 strains produced acid under anaerobic and aerobic conditions; strain A‐1 produced more than the others. Lactic acid accounted for 30–51% of the acid produced in all strains. Strain A‐1 more closely resembled the nasal trichomonad of swine (strain PN‐610) than did strain BP‐1. (Doran(3)). The writer believes that the swine nasal strain is a highly adapted strain of T. foetus.

SYNOPSIS. The establishment of Eimeria acervulina sporozoites in the duodenal glands of Lieberkühn of the chicken is described. Sporozoites were found to enter the tips of the villi and pass into the lamina propria, or core, of the villus. Within the lamina propria, sporozoites were engulfed by macrophages and taken to the glandular epithelium. Data are presented which indicate that macrophages serve as a defense against infection as well as a mode of transportation.

Eimeria tenella sporozoites were inoculated into primary cultures of chick kidney cells. Cells fixed from 1 1/2 to 54 hr later were examined with the electron microscope. At 1 1/2 and 24 hr, most intracellular sporozoites were fusiform and retained organelles typical of extracellular sporozoites. However, at 35 hr, rounded trophozoites were present without these structures; only a refractile body, nucleus, mitochondria, and endoplasmic reticulum remained. Binucleate parasites were also present at that time, but at 48 hr many multinucleate schizonts were present. Nuclei, with adjacent conoids, were at the periphery of these schizonts. Partly developed merozoites, each containing a conoid and a nucleus, protruded into the parasitophorous vacuole. At 54 hr, fully developed merozoites were separated from the residual body. Merozoites resembled sporozoites but lacked the large refractile bodies seen in sporozoites. Linear inclusions were present near the merozoite nucleus and in the residual body. Round vacuoles and ribosomes were also found in the residuum. Nucleoli were first seen in sporozoite nuclei at 1 1/2 hr. They were also present in merozoites but were more prominent in trophozoites and schizonts. Peripheral and scattered nuclear heterochromatins were prominent in intracellular sporozoites and diminished in trophozoites, but increased after several nuclear divisions and were again prominent in the merozoite. Small, distinct interchromatin granules were found in all stages. Intranuclear spindles, centrocones, and centrioles were found in connection with nuclear divisions. Ultrastructure of first-generation schizogony in cell culture was similar to that described for second-generation E. tenella in the chicken and to schizogony of other species of Eimeria.