1. The fat content of the skin and of the skin-free carcass was measured in young, growing hairless mice about 4-8 weeks old kept at either 22° (cool environment, i.e. below their critical temperature) or at 33° (warm environment; i.e. within their thermoneutral range). The food intake of groups of the mice reared at each temperature was restricted to between 77 and 89 % of that of a litter-mate fed ad lib.

2. In all the mice, whether fed ad lib. or on a restricted intake, those reared in the warm environment contained about 1.5 times as much fat as those reared in the cool environment. At both temperatures and feeding levels, approximately 25 % of the total body fat was present in the skin.

3. Each mouse reared at 33° on an ad lib. regimen reached about the same plateau weight in the same period as its litter-mate reared at 22°. However its food intake during this period of growth was only about half that of the mouse reared at the lower temperature, so its food conversion ratio (dry food intake: body-weight gain) was twice as efficient.

4. It is concluded that neither the growth rate nor the distribution of fat within the body of the growing mouse can be influenced by rearing the animals at these different environmental temperatures. Rearing at the higher temperature, however, both decreases food intake and also promotes deposition of more fat within the body.

1. Rats were undernourished in early life by feeding their mothers a restricted quantity of a good-quality diet throughout lactation. Their undernutrition continued postweaning from 25 to 42 d of age, after which they were fed ad lib. Control rats were well nourished at all times.

2. Behavioural assessment of thirst was carried out on adult males. These were deprived of water for 23 h/d throughout the period of testing. Compared to control rats, previously-undernourished (PU) rats pressed a lever at a higher rate in a Skinner box to gain a water reward, drank more frequently during their first 5 min in an unfamiliar cage, and tended to run more quickly down an alleyway for water. PU rats also drank more (/kg body-weighta0.75) of a quinine solution (1 g/l) when this was available to them ad lib. as their only source of fluid.

3. A second group of rats was growth-retarded during gestation and the suckling and early postweaning periods. The rats had free access to food from 42 d of age. In adulthood their ad lib. food and water consumption was measured. PU males ate and drank more (/kg body-weight0.75) than control males.

4. These results indicate that adult rats which have been undernourished in early life display increased thirst. An attempt is made to explain this finding, together with their previously-demonstrated enhanced hunger drive, purely in terms of gross anatomical and physiological differences.

1. A comparison has been made of the products of lipolysis of the fat in cow's milk by salivary and pancreatic lipases (EC 3.1.1.3) from a preruminant calf.

2. It was confirmed that salivary lipase releases short-chain acids preferentially, particularly butyric and caproic acids. This was not only true initially but also as the course of lipolysis progressed. Even after 60 min incubation the longer-chain acids were only released to about one-twentieth of the extent of butyric acid.

3. Although pancreatic lipase also initially released proportionately more butyric acid than other fatty acids, within 30 min the longer-chain acids were released to about half the extent of butyric acid.

4. Since the over-all extent of lipolysis by salivary lipase was limited by its inability to release long-chain acids, the release of these acids (which comprise two-thirds of the total fatty acids of milk fat) in the calf is likely to be dependent on the subsequent action of pancreatic lipase.

5. The release of fatty acids by pancreatic lipase was enhanced by pre-incubating milk fat with salivary lipase.

1. Na234SO4 was infused into the rumen of a sheep fed a dried grass diet.

2. The digesta at the pylorus which contained 35S-labelled cyst(e)ine synthesized by the rumen microflora was collected and mixed with chromium EDTA. This material was infused into the duodenum of 35S free sheep.

3. Ileal digesta was subsequently collected and analysed for cyst(e)ine 35S and Cr.

4. The proportion of the labelled cyst(e)ine truly absorbed from the small intestine was 0.72±0.004.

1. Growth in weight and height in 152 children between the ages of 0.6 and 3 years was investigated in Keneba, a rural Gambian village. By 1 year of age the average weight-for-age of the children was only 75% of the Jelliffe (1966) standard.

2. The relationship between the prevalence of nine different categories of diseases and growth was investigated to determine the quantitative contribution of the diseases to the growth faltering observed. There was a highly significant negative relationship between gastroenteritis and both weight gain and height gain. The only other disease category having a similar relationship was malaria, but in this instance only with weight gain.

3. Although over-all growth in weight and height was considerably below the standard values, multiple regression analysis indicated that after the age of 1 year, except in July and August, normal and sometimes slow ‘catch-up’ growth would be possible in the absence of gastroenteritis.

4. Attention is drawn to the limitations of the use of anthropometry in a settled village community as the only criterion by which dietary adequacy can be judged.

1. The retention of ferric- and ferrous-iron was determined in guinea-pigs and monkeys using 55Fe and 59Fe.

2. The bioavailability of Fe from two typical Indian diets based on rice and wheat was determined in humans and monkeys using a 59Fe tracer and whole-body counting.

3. The retention ratio, ferric-Fe; ferrous-Fe was 0.90 in guinea-pigs and 0.33 in monkeys, indicating that monkeys absorb ferrous-Fe preferentially.

4. In monkeys retention of Fe from the test diets, as from ferrous ascorbate was lower than that in humans.

5. When food-Fe retention was expressed in relation to inorganic-Fe retention the value for retention ratio, food Fe: inorganic Fe in monkeys was similar to that in human subjects.

6. The results indicate that the monkey can be used as a model to study Fe absorption from human diets.

1. A relationship was found between selenium concentrations and glutathione peroxidase (EC 1.11.1.9) activities in whole blood of 264 New Zealand residents (r 0.71, P < 0.001).

2. New Zealand residents returning from visits overseas of 7 months to 3 years had elevated blood Se, but normal GSH-Px activities, whereas for some new settlers in New Zealand both Se and GSH-Px activities were high.