1. Erythrocytes from Ugandan children with untreated kwashiorkor had membranes containing larger amounts of lecithin than erythrocytes collected during the recovery phase.

2. The passive permeability of the erythrocyte membrane to glycerol and thiourea was reduced in kwashiorkor and returned to a more normal value on treatment.

3. The results are discussed in the light of similar findings of high erythrocyte lecithin concentrations in various liver diseases.

1. A comparison of human tissue organo-bromine residues has been made from specimens obtained in the UK, West Germany and Holland.

2. These findings, in conjunction with previous animal studies and with the geographical differences in the use of brominated vegetable oils as food additives, suggest that the high bromine levels found in the fat of tissues from UK children are due to the use of these compounds.

1. Experiments are described in which the food intake and the water intake of sheep at a single meal were measured. The sheep were offered lucerne chaff ad lib. for 2 h only each day.

2. Following the peritoneal infusion of physiological saline the food intake increased, while the injection of a diuretic before feeding caused the food intake to be decreased.

3. In eight experiments the osmolality of the ruminal liquor was increased by the addition to the rumen of NaCl, KCl or the salts of volatile fatty acids in 250 ml water. The decrease in food intake was related to the osmolality, but not to the energy content, of the added electrolyte solution. In a further experiment, sheep receiving a highly digestible lucerne chaff, containing 1% (w/w) NaCl, increased their food intake when water was added to the rumen. Other workers have concluded that gastric osmolality is an important variable in the control of food intake in monogastric animals. The results of the eight experiments now described suggest that ruminal osmolality is of similar importance in ruminants.

4. It is suggested that all these observations are consistent with the theory, which has been proposed for non-ruminant animals, that the food intake at a single meal may be related to the degree of tissue hydration at the beginning of the meal.

1. A technique for the separation and colorimetric estimation of 2, 4-diaminopimelic acid (DAP) using automated ion-exchange chromatography coupled with an acid ninhydrin detection system is described.

2. Only traces of DAP were found in rumen protozoa and no DAP was detected in rumen fluid prepared by ultracentrifugation or dialysis.

3. The concentration of DAP in rumen bacteria from sheep on a constant feeding regimen, and the ratio of nitrogen to DAP for these bacteria were found to be constant over a 3-month period.

4. The method has proved suitable for the estimation of bacterial N in the duodenal digesta of ruminants.

5. The contribution of bacterial N to the total N leaving the abomasum of a lactating cow fitted with a permanent re-entrant cannula in the duodenum was found to be 50%.

1. Rats born of well-fed mothers and maintained from weaning on diets having protein values of NDpCal% = 10 or 5 were mated at 3 months of age with well-fed males.

2. The litters produced by the malnourished mothers weighed significantly less (P > 0.01) than those from the well-fed group.

3. The average number of individuals per litter was lower in the malnourished than in the well-fed group, but the difference was not statistically significant ( P < 0.0 5 ).

4. The congenitally malnourished litters weighed less than the well-fed even when litters of equal number were compared.

5. The differences in litter weights were not related to the length of gestation, which was similar in both groups.

6. There was a high neonatal death rate (63%) among the congenitally malnourished animals and the survivors grew very slowly so that at 5 weeks of age they weighed only half as much as the well-fed controls.

1. Concentrations of nucleic acid nitrogen and other nitrogenous constituents were estimated in digesta taken from the proximal duodenum of calves which were given, either, one of a number of stall diets or pasture. These concentrations were compared, using polyethylene glycol (PEG) as a non-absorbed marker, with corresponding concentrations in rumen fluid and ileal contents.

2. There was little net change in amounts of RNA or DNA between rumen and duodenum relative to PEG, but there was a marked increase in amounts of total-N. In duodenal digesta, for any one animal given most diets, nucleic acid-N formed a fairly constant percentage (8–11 for different animals) of the total non-ammonia-N. This value was lower (by about 3) than the corresponding percentage in rumen fluid. Comparison of nucleic acid-N: total-N ratios in duodenal contents and bacteria suggested that, for these diets, about 40–55% of the non-ammonia-N in duodenal contents was of microbial origin.

3. During passage of digesta between the duodenum and ileum the mean percentage disappearances of total-N, RNA and DNA were estimated to be about 67, 85 and 75 respectively. There was evidence that these values varied with the amounts of the constituents entering the duodenum.

4. Ammonia was absorbed in the omasum-abomasum only when concentrations in rumen fluid were high (40 mM), but even moderate concentrations of ammonia entering the duodenum (3 mM) were efficiently absorbed (about 90%) in the small intestine.