1. An experiment on pullets combining daily calcium and phosphorus balance determinations with carcass analyses is described.

2. It is shown that fat content of pullets is affected by the calcium content of the ration. The fat content was higher on a low calcium ration than on a high calcium ration.

3. The CaO content of pullets was raised considerably by feeding a high calcium ration before laying. This CaO must have been stored in the bones, which contained between 97·2 and 98·7% of all the CaO in the body.

4. The experiment suggests that pullets may use up to about one-quarter of their body calcium at the outset of laying for purposes of shell formation.

5. The composition of the inorganic material of the skeleton of pullets may be modified by alterations in their mineral metabolism due to egg production on diets with and without a calcium carbonate supplement. The nature of these modifications and their relationship to calcium metabolism during laying is discussed.

1. The method described in an earlier paper for measuring the compressibility of soils in situ has been used to study the gradual consolidation of soil following digging with a fork, and a new method in which the rate of flow of water through rubber tubes buried in the soil gives a measure of compression, is described.

2. By means of this latter method some measure can be obtained of the changes that take place in the soil after it has been loaded and trampled.

3. The results of the experiments confirm and amplify the earlier conclusions. Without further data it is hard to distinguish quantitatively the effects of moisture and time, but it is of interest that whereas the compressibility of newly dug soils is hardly affected by differences in moisture for the range of stress used, that of soils which have rested for some time since cultivation is much increased by an increase in moisture content.

4. Experiments on a wider scale should be undertaken in order that a more complete analysis may be effected.

Individual analyses of forty Light Sussex cockerels of twenty-two weeks of age yielded the following results:

1. There is a highly negative correlation between the fat percentage of the carcass and the moisture percentage.

2. Owing to the large variability in the fat content of individuals, live-weight increases are unreliable as a measure of energy storage.

3. Comparison of the fat content of the bones with that of the flesh and offal leads to the conclusion that the bones as well as the flesh and offal play a significant role in the general fat metabolism of the body.

4. There exists a strongly positive correlation between the ash content of the bones and that of the flesh and offal.

5. The protein ash ratio of both the Light Sussex breed and the White Leghorn breed is practically constant for all individuals after the age of seven weeks, indicating that the growth of the skeletal and the muscular tissues are closely correlated and controlled by the same growth impulse.

6. The individual variation in energy content is shown to be ± 11.42% of the total energy content.

The low temperature ignition of soil organic matter has been investigated for temperatures ranging from 100 to 500° C.

Appreciable losses are found to occur below 100° C.; up to 200° C. heating results essentially in the distillation of volatile constituents, while between this temperature and 300° C. destructive distillation is the major reaction. These reactions are responsible for the removal of 85% of the soil organic matter.

By 300° C. the greater part of the residual organic matter consists of carbonaceous material, and the final reaction is simple ignition of this material.

Two hours’ heating of the soil at 450° C. or about half an hour at 500° C. are recommended for the removal of 99% of the soil organic matter.

1. In two experiments on heavy land (one continued for four, and the other for three years) gyrotilling has been compared with normal cultivations, and no significant increase in yield has been obtained, although in five out of seven experimental crops the actual difference was very slightly in favour of gyrotilling.

2. In two experiments on light land (one continued for three, and one for two years) gyrotilling has been compared with normal cultivations (ploughing and subsoiling, and also, in one case, ploughing alone), and in all five experimental crops there was a slight depression in yield, which was only significant in one case, connected with gyrotilling.

The method suggested by Papadakis of using covariance with the yields of neighbouring plots to reduce the error of replicated field experiments is illustrated on two large-scale cotton experiments. In a discussion on the validity and value of the method, it is concluded that for such experiments, where the number of plots per block is large, the method should be approximately valid and sometimes useful.

1. The vitamin A content of the colostrum of one hundred cows, kept under the same conditions of dietary and management, was found to range from 1181 to 35 I.U. per 100 ml.

2. It has been established that this wide range was not due to any differences in dietary, breed or date of calving in animals kept under the same conditions of management.

3. It is suggested that the vitamin A content of the colostrum may be materially affected by the length of the non-lactating period between successive calvings.

The fact that land which frequently bears a crop of clover becomes rapidly unfit to bear further crops of this plant is a very old observation in all countries where clover is grown. In England, Arthur Young (1804) called attention to it and to the fact that farmers were accustomed to call this unfitness “clover sickness”. The cause of this soil condition has been a matter of careful study since early in the nineteenth century, and some of the most interesting observations on the subject were made by Lawes & Gilbert (1860) in the years preceding 1860. They showed that the lack of capacity to grow clover did not seem to be connected with any deficiency in the principal specific plant foods in the soil, and the only contrary evidence was the fact that when a rich garden soil was substituted for the ordinary field soil, it was possible to grow clover for a much longer period without failure (Gilbert, 1871). The final conclusion of Lawes & Gilbert as to the so-called clover sickness was that the only means of ensuring a good crop of red clover is to allow some years to elapse before repeating the crop on the same land.

1. Comparative analyses of pyrethrum flowers have been carried out by the methods of Tattersfield, Seil, Ripert, Haller & Acree and Wilcoxon.

2. The methods were of value in indicating the relative richness in pyrethrins of the samples tested, but discrepancies were seen in the absolute values of the pyrethrins I and II recorded. Under present conditions and until a standard method of analysis is agreed upon, it would appear requisite to state the method employed in the evaluation of the flowers.

3. The Wilcoxon method has given higher figures for the pyrethrin I content than the Seil method. The degree of divergence between the results depended upon the richness of the flowers, and upon the excess of acid used in distilling the volatile acid in the Seil method. The relationship between the amount of the pyrethrin I acid present and the titration recorded in the Wilcoxon method was not a linear one.

4. The question of the solvent to be used for the initial extraction of the flowers has been briefly discussed.

1. The high grain-yielding capacity and low total nitrogen content of predominant British varieties of barley, in conjunction with high ear survival at harvest, are discussed.

2. The results of a series of quantitative comparisons in which increased tillering was promoted by the application of nitrate of soda at various phases of plant development, and similarly when tillers were removed at various stages, were examined.

3. It was shown that the effect of nitrogen on the yield and quality of the grain depends upon the time in relation to the stage of plant development at which it was applied; the early applications enhanced the yield without detriment to the quality of the grain, whilst the later applications did not increase the yield but increased the total nitrogen content, and consequently reduced the malting quality of the grain.

4. The increase in yield was obtained primarily by an increase in the number of surviving tillers and to a less extent by an increase in yield of grain per ear; the latter was in some cases accompanied by an increase in 1000-grain weight. High ear survival in varieties such as those under examination may consequently be regarded as an index of high yield of grain and of low total nitrogen content.

5. The removal of tillers resulted in increased total nitrogen content and increased 1000-grain weight in the grain of the main stem; the former was not affected by the stage of development of the plant at which abscission was made, but the highest value of the latter was obtained when the abscission was made before flowering.

6. The relation of 1000-grain weight and nitrogen content was discussed, and it was shown that high 1000-grain weight may exist with both high and low total nitrogen. Although the 1000-grain weight is an hereditary attribute it is subject to considerable fluctuation and cannot by itself be usefully employed as an index of nitrogen content, and consequently of malting quality, in either an inter- or intra-varietal sense.

In the spring of 1937 an experiment was conducted to test existing commercial facilities for the transport of bull semen between England and Holland. Samples were sent to and received from Holland via Royal Dutch Air Lines, to whom the authors wish to express their sincere thanks for most useful co-operation. The minimum interval between collection in one country and insemination in the other was 28 hr. and the maximum, 57 hr.