1. The seeding rate of radish seed may be influenced by the mechanical effect of the material with which it is treated.

2. The seedling emergence of radishes may be improved by treating the seed with an organomercury seed disinfectant.

3. The beneficial effect is correlated with adverse weather conditions at the time of germination, and advantages are therefore usually confined to early sowings.

An account of the agricultural conditions which influence the development of stem-end blackening in cooked potatoes has recently been given (Wager, 1946). The evidence given by Smith, Nash & Dittman (1942) shows that the average air temperature for the three weeks preceding the lifting of the tubers, or the death of the tops, controls the development of stem-end blackening in the tubers and the authors claim that this is an overriding factor. In their experiments, extending over several years, little or no blackening developed when the average air temperature was between 70 and 80° F., when between 60 and 70° F. there was a medium development of blackening and when between 50 and 60° F. there was much blackening.

The wool production of a small flock of Romney Sheep has been studied for a few years. When the sheep were 1 month old squares were tattooed on to four regions of each sheep.

The weight of wool from, and the area of, these squares has been studied.

We find that, under good growing conditions, for the same region, all sheep produce the same weight of wool per sq.cm. of skin per day (denoted by c), which is independent of age, seasons, year of birth of sheep, but varies from region to region, being higher the nearer the region to the mid-dorsal line.

When conditions are unfavourable the weight of wool a particular sheep produces from a particular region falls below the c value for the region, approximately, by a factor (1 – B/E), where E is the skin expansion ratio of the particular region and B is a number, the same for all sheep and all regions in one season and is greater the worse the season.

I am particularly indebted to Dr Hammond, School of Agriculture, Cambridge, and to Mr W. S. Kelly (Australia) for help and advice, and to the Animal Research Station, Cambridge, for providing the facilities for working with sheep. I wish to express my indebtedness to my colleagues of the Biology Department of this Association who have assisted me in various ways, and to Dr Daniels for help with the statistical treatment of the data, and to Mr R. C. Palmer for criticism and help in preparing the results for publication. My thanks are due to Mr B. H. Wilsdon, Director of Research, for his encouragement, to the International Wool Secretariat for providing the sheep, and to the Council of the Wool Industries Research Association for permission to publish the results.

1. In pony mares during oestrus in which a follicle was considered to be sufficiently ripe (thin walled) the intravenous injection of 500 i.u. pregnancy urine extract induced ovulation in nineteen out of twenty-three mares between 24 and 48 hr., in three cases within 24 hr., and in one case between the fourth and fifth days.

2. Dialysed egg yolk as a medium for storage of horse sperm for 24 hr. was shown to give satisfactory results when ovulation is controlled by the above method, so that it occurs within 24 hr. after insemination. Nine single inseminations during one oestrus resulted in five pregnancies.

3. The number of spermatozoa required for successful inseminations is discussed.

4. Means of detecting a sufficiently ripe follicle before injection with pregnancy urine extract are described.

5. It is shown that the duration of oestrus is shortened as the result of pregnancy urine injections.

6. Data is given concerning the time which elapses between ovulation and the cessation of oestrus.

1. For experimental purposes the treatment of cotton seed with sulphuric acid, prior to planting, has always been the custom at Barberton. In view of the doubts about the benefits of this treatment which were expressed by Christidis (1936), experiments were carried out at Barberton in the 1938–9 and 1939–40 seasons, to provide concrete proof, if possible, of the advantages which it was believed resulted from it.

2. A series of stand counts made soon after germination revealed definite benefits with acid treatment, in all experiments in both seasons. The seedlings emerged considerably earlier than those from untreated seeds, and the stands recorded at the final counts revealed a significant advantage for acid-treated seed, throughout the experiments. The second season's experiments gave a greater advantage for acid treating when meteorological conditions were bad than when they were good, but the advantage even with ideal weather was still significant. The benefit of acid treatment was shown to be greater, too, with poor samples of seed than with good, and with the smaller seed rate than with the greater.

1. Experience raised doubts as to the usefulness of filling gaps in bad stands of cotton at Barberton and experiments were conducted in two seasons to measure its effectiveness. The experiments gave clear-cut results.

2. Randomized gaps ranging from 20 to 40% of the stand were filled and left open for comparison, the filling being done 13 and 19 days after planting.

3. Any reduction in stand, though reducing yield per acre, led to large and significant increases in yield per plant, even when the spacing was 3 by 3 ft., wider than that normally used on the Station.

4. Replanting the gaps in a bad stand did not lead to any increase in yield per acre; there were, in fact, indications that this practice actually reduced yield per acre, the refills preventing plants of the original sowing from benefiting fully from the extra space available to them in a bad stand.

5. The general conclusion is that no useful purpose is served by refilling the gaps in poor stands of cotton with up to 40% of gaps.

The effect of beet yellows virus on the yield of sugar beet was tested in the presence and absence of various fertilizers and farmyard manure. In general the manorial treatments increased the root and sugar yields of both infected and healthy plants, but the losses caused by infection increased proportionally as the mean yields increased. When the effects of nitrogen, farmyard manure and salt on mean yield were large, the losses caused by infection were increased more than proportionally.

The fertilizers had little effect in varying the symptoms of the disease. There was some indication that the red colour associated with some varieties of sugar beet was intensified by deficiency of phosphate and potash.

The effect of fertilizers on rate of spread of infection was variable, and again appeared to depend largely upon the magnitude of the fertilizer effects on mean yield. Nitrogen, phosphate and potash occasionally had positive effects, and salt had a fairly consistent negative effect. None of the effects appeared to be of any economic importance.

The wartime expansion in the home production of grass, clover and other seeds raised the question of the value of such seeds as food for livestock, since during the later years of the war, surpluses that had been discarded on account of low germination or other causes were being sold to compound manufacturers for inclusion in cattle foods. During 1944, the writers made determinations of the digestibility and starch equivalents of the following seeds: ryegrass (a mixture of Italian and Perennial), red clover, lucerne and un-milled sainfoin. All the samples were reduced to a fine meal before being submitted to test in the digestion trials.

Apart from its lower content of digestible ether extract, ryegrass-seed meal resembles oats in respect of chemical composition, digestibility and starch equivalent. It is a carbohydrate concentrate, containing, on the dry matter basis, 69·4% of starch equivalent, including 7·3% of digestible protein.

1. An experiment on the riboflavin requirement of the White Wyandotte chick is described.

2. The minimal requirement for optimal food consumption was found to be 3·0 μg. riboflavin/g. food; for optimal growth 3·0 to 3·5 μg./g. food and for the prevention of curled-toe paralysis 3·6 μg./g. food.

3. At levels of riboflavin intake ranging from 1·7 to 6·2 μg./g. food the uric acid content of the blood plasma remained unchanged at approximately 6 mg./100 ml.

1. Experiments are described in which the riboflavin contents of the liver, kidney, heart and leg muscles of chicks were assayed during the first few weeks after hatching, using birds reared on both riboflavin-deficient and riboflavin-adequate diets.

2. Changes in the composition of the liver during the first 3 weeks after hatching have been studied.

3. At hatching, half the chick's liver consists of oil; this proportion is maintained during the first week, but falls to about one-eighth during the second week and maintains this level during the third week.

4. When birds are reared on a riboflavin-deficient diet, the riboflavin concentrations of the heart and kidney are reduced more rapidly than that of the leg muscles.

The blood copper of normal sheep from the Institute flock at Cambridge was studied over the period October-April for three lambing seasons and showed no changes characteristic of pregnancy; in contrast to the behaviour of human beings and possibly sheep of low copper status. What changes there were took place in both pregnant and nonpregnant sheep, did not reflect the transfer of copper to the foetus and appeared to be due to extrinsic factors.

Comparison of the blood copper of the lamb with that of its dam for four lambing seasons showed that it was a changing quantity at birth, being lower in the foetus, variable a few hours after birth and higher some days later than in the ewe.

The blood copper of suckling lambs was studied from birth in February-March until June, for three seasons. There tended to be high values in the first 1 or 2 weeks of life, which decreased in the course of approximately 10 weeks.

The copper, iron and lead contents were determined on an age series of foetal livers obtained during the latter half of pregnancy from normal ewes at Cambridge. The total amounts of the metals showed a rapid rise during the last 3 weeks of gestation due to an increase in the size of the organ and in the actual concentrations. Towards full term and in the new-born animal the results showed an increasing variation which even extended to twins. It is noted that foetal transference takes place without affecting the blood copper of the ewe or causing a physiological anaemia of pregnancy. The time at which the process is at its height is correlated with experience in the prophylaxis of swayback. It is estimated that the store of copper at birth may tide the lamb through the suckling period but the store of iron requires to be supplemented by the diet and that the ewe's milk may make a significant contribution towards this. The small amounts of lead found were of the same order as reported for normal humans and in swayback lambs in Derbyshire; hence the latter cannot be regarded as abnormal.