1. An experimental study has been made of the effects of heat, light, air, enzymes and bacteria on carotene destruction, when green fodder is dried and stored as hay.

2. Carotene in green fodders can be destroyed by autoclaving or other forms of heating in the presence of air. The extent of destruction depends upon the period of heating.

3. Carotene is not destroyed if green plants are dried in a vacuum.

4. Atmospheric oxygen plays the predominant part in the destruction of carotene; and heat, light and moisture are merely accelerating agents. The destruction of carotene during storage is due mainly to a slow spontaneous oxidation of the pigment in plant material.

5. The utility in India of grass drying or hay making with the specific object of providing vitamin A supplements is questionable, because of the carotene destruction during storage under prevailing temperature and climatic conditions.

The results of carotene metabolism experiments with four cows and four bullocks have been discussed. It has been shown that under ordinary farm diet, cows may secrete milk with a fair amount of carotene and vitamin A potency and still themselves remain on negative carotene balance, so far as the current intake and outgo are concerned. Increased intakes of carotene are, however, followed by the increased carotene and vitamin A potency of milk. Experiments with bullocks on a carotene-low diet consisting of dry rations have shown that the faecal carotene elimination attains a constant value and the animals show a consistently negative carotene balance. When, however, two doses of berseem are superimposed on this basal ration, positive retentions of carotene are obtained, followed by a rise in the blood-carotene level. The experimental evidence points to the possibility of a part of the faecal excretion being the result of a withdrawal of carotene from the body reserves.

The relative unreliability of Bouyoucos's suction method for moisture equivalent determinations is a consequence: (1) of the variation of the suction force maintained with the nature of the soil, (2) of bad reproducibility of the results.

Constant and equal suction for all soils is secured by Schofield's silt-suction method, which may also be made to give fairly well reproducible results. The moisture content at pF 2·9 determined by this method should give a fairly close measure of the moisture equivalent.

While investigating this possibility it was found that the pF curves of stored soil samples may shift considerably with time. In the samples studied the pF at the moisture equivalent has dropped from 2·9 to about 2·4 in 7 years. In view of this shifting the reliability of the silt-suction method for moisture-equivalent determinations has not been definitely ascertained by the experiments reported.

1. The mean pH of 221 ejaculates of clinically normal bulls was 6·73 ± 0·020. Significant differences were noted between different bulls.

2. There were highly significant negative correlations between the pH. of the ejaculates and the concentration of spermatozoa, the volume of ejaculate and the motility of the spermatozoa.

3. The more acid the semen was on collection, the better was the motility retained on storage. Semen which retained its motility well became increasingly acid during storage. A change in the pH in the alkaline direction during storage had an adverse effect on motility. The more acid the pH on collection the less likely was a decrease in acidity during storage.

1. Gonadotrophic extracts of horse-pituitary gland, of pregnant mare serum and of urine of pregnant women, as well as oestrogenic substances, will induce ovulation in anoestrous sheep. The number of ova shed is apparently independent of the dosage given and lies within the normal range.

2. The oestrogens probably act by evoking ovulation-producing activity on the part of the animal's own pituitary gland, and it is likely that the gonadotrophins also initiate the same chain of events by causing oestrogen secretion by the ovary.

3. Oestrogens induce heat in the anoestrous sheep, but horse-pituitary extract and P.M.S. evoked sexual receptivity only in animals having a regressing corpus luteum. In the absence of a corpus luteum, ovulation occurs without heat, while the presence of an active corpus luteum usually suppresses both ovulation and heat.

4. Administration of horse pituitary a few days before the corpus luteum is due to regress results in superovulation at the succeeding heat, as many as twelve simultaneous ovulations having been obtained under these conditions.

In an experiment with twenty-four Large White pigs fattened from weaning to bacon weight on a diet containing either 5 or 9% of dried Clostridium residues the latter was found to be an efficient protein supplement.

The authors wish to express their thanks to Dr S. J. Rowland who made all the chemical analyses involved, to the Directors of Commercial Solvents G.B., Ltd., who kindly supplied the product, and to Mr E. Gill, Works Manager of the above Company, for helpful collaboration.

Experiments on the effect of inter-row cultivation of sugar beet, carried out in the three years 1939–41 on a sandy loam, led to the following results:

1. If the soil nutrients are in short supply hoeing or hand-weeding increases the yield of the beet, provided these operations are carried out before or shortly after singling.

2. Hoeing is more effective than hand-weeding, but it cannot yet be said with certainty whether this is due entirely to more efficient weed destruction, or whether there is some additional effect, such as mulching.

3. If adequate quantities of soil nutrients are present, inter-row cultivation has little effect on yield, and the crop can tolerate a considerable weed infestation without any effect on yield.

The results for sugar beet on the heavy clay-with-flints soil at Rothamsted show:

1. Additional hoeings after singling, above a modest minimum, have either no effect on yield or else depress it.

2. On the one occasion when pre-singling cultivations were given, the yield was increased.

3. In contrast with the Woburn results the effect of cultivation does not vary with, the level of manuring.

1. The average electrode potentials of laboratory silages of various types have been measured.

2. The electrode potentials of ordinary and molassed silages tended to assume values of the order of –0·05 to –0·10 V. from about the third day; the pH of these silages lay in the range pH 4·0 to 5·5.

3. In a number of instances secondary increases of electrode potential were observed, frequently in association with secondary deterioration.

4. The electrode potential of silage prepared with hydrochloric acid and of pH 3·4 remained steady around +0·18 V.; the potential of silage prepared with formic acid and of pH 3·9 was about + 0·35 V. initially but declined towards + 0·23 V. at 35 days.

5. Curves for the ‘pure’ carotene content of laboratory silages displayed minima during the early stages of fermentation except in the case of formic acid silage.