Fat colour is of importance in beef produced for English markets because of discrimination against deep yellow fat. The factors at present known to affect colour are genetic(1,4) and those relating to food supply(2,3), but not much is yet known of the various circumstances or natural conditions under which the colour will vary in shade. It was the purpose of this investigation to determine some of these. Rabbits were selected for the preliminary experiments, as, although it is questionable whether the colouring matter in the fat is quite the same as in cattle (3, 5), it is very probably affected by the same conditions. Experiments could be done quicker and cheaper in rabbits than in cattle on which the results could be tested after the pioneer work in the rabbit was completed.

The effect which different varieties grown on small plots side by side may have upon each other is usually termed competition. Naturally if a tall variety, or one having a root system highly developed, is planted on small plots in alternation with a short variety or one with small roots, it is to be expected that the latter will suffer from the unfavourable neighbourhood, whereas the former will be benefited. In other words, when testing varieties differing in their habits of growth, etc., owing to the effect of competition some of them may appear better and others worse than they are under natural conditions.

Feeding stalls of the Lehmann type, which are generally employed when sheep are used for digestibility trials, are useful if wethers act as experimental animals. The wether, however, is not an ideal subject for investigations in which it is desired to estimate the utilisation of individual nutriments, for the portion of the ration which is retained usually constitutes but a small part of that ingested and, in consequence, when attempts are made to draw up a true balance considerable errors are often encountered through the difficulty of ascertaining the total volume of urine excreted during the feeding period. This uncertainty may be overcome, for if the ewe is used a catheter may be passed into the bladder and the urine completely drained at the will of the experimenter.

The experiment was designed to compare under Trinidad conditions three varieties of fodder grass and ascertain the correct stage at which each should be cut to give the maximum nutritive value per acre. It consisted of a yield trial in the form of a Latin square in which the treatment series included four cutting rotations on main plots and three varieties of fodder grass on subplots as appended

The results of a winter nutrition experiment on dairy cows were used as a uniformity trial in order to indicate the magnitude of the standard error we may expect if a continuous treatment experiment is designed with a preliminary control period.

An initial period of three weeks is suggested, and some discussion given on the design and analysis of this type of experiment.

1. Exp. I was conducted with two pigs in each group, which pigs were kept during certain times in digestion boxes, permitting the separate collection of faeces and urine.

2. The total amount of food given to the pigs was slightly below the present standards.

3. The different rations contained different amounts of protein and different amounts of non-nitrogenous constituents.

4. Exp. II was conducted with one pig in each group and served to control and supplement the data collected in the previous experiment.

1. The question whether the amount of cystine in the wool grown may exceed that in the diet is discussed.

2. When 1 gm. of laevo-cystine was added to the daily ration of a ewe on a low protein diet, the wool grown upon a circumscribed area was 14 per cent, more than that grown during a similar period immediately preceding. Four-fifths of the sulphur in the added cystine was absorbed, about half of which was excreted in the urine during the period the cystine was being fed.

3. When 1 gm. of laevo-cystein was injected subcutaneously each day for 10 days, a 34 per cent, increase in wool growth occurred. During three succeeding periods, of 10 days each, immediately after the injections had been discontinued, the increases were 30, 18 and 7 per cent, respectively. Of the 2.6 gm. of sulphur in the cystein injected during the 10 days, 1.7 gm. was retained and could be accounted for by the extra amount of wool grown during that and the succeeding periods.

The estimation of the experimental yields of cereal crops by sampling methods is considered in the light of results of eighteen experiments which were harvested by these methods at Rothamsted and its associated centres. The harvesting results of the Crop-Weather series of experiments are also included.

A preliminary discussion of the interpretation of the analysis of variance as applied to sampling results is given, and an expression is found for the loss of information arising out of sampling. The results of the discussion are applicable to all types of sampling carried out on replicated experiments.

The sampling and experimental errors of all the experiments have been calculated. The variation between sampling units in the same subplot (usually between l/100th and l/200th acre) was found to be such as would arise if each metre length of row had a standard deviation (about the plot mean) of the order of 25–30 per cent. of the mean yield.

1. In pot culture experiments with barley and mustard conducted in several soils over a number of years, the yield differences between calcium cyanamide and ammonium sulphate were generally small. Calcium cyanamide gave slightly poorer results than ammonium sulphate in soils with high responses to added nitrogen but definitely better ones in soils which contained much available nitrogen and in which calcium cyanamide greatly retarded nitrification.

2. The pot culture experiments confirmed the conclusion from earlier laboratory work that in normal soils calcium cyanamide was converted through urea into ammonia within a few days. Nitrate accumulation was less complete and slower from calcium cyanamide than from ammonium sulphate. In one soil the nitrogen from calcium cyanamide remained as ammonia for several weeks, the nitrate content being below that even of unmanured soil.

The original object of the breeding investigations described above was to secure a new variety of oats exhibiting the resistance to winter conditions and the grain quality characteristic of Grey Winter, in combination, if possible, with straw of better standing power.

The characters of the hybrids studied in the course of the investigations were accordingly resistance to winter conditions, standing power of the straw, quality of the grain, and the early growth habit, particularly in relation to these three features.

1. Low temperature grain pre-treatment of some varieties of wheat, barley, and oats, has resulted, in most cases, in a stimulation to early development of the plant with a modification of the juvenile habit.

2. In addition to early developmental stimulation, winter varieties of barley and wheat also showed marked acceleration in the date of earing. Spring varieties either failed to show this earing acceleration or else were but slightly affected.

3. Glasshouse culture during the first few months of growth resulted, in most varieties, in a greater response to the grain pre-treatment. It is suggested that this was due to the absence of low temperatures in the glasshouse.

In this paper are brought together a number of data concerning the ratio of the amount of leaf to stem in the lucerne crop, at different stages of growth, and the separate composition of the leafy and stemmy fractions.

It is shown that the proportion of leaf falls off as the crop advances in maturity, and that the rate of decrease of leafiness is greater before budding than during the period from the beginning of budding to early flower. The changes in the leaf-stem ratio largely account for the fall in protein content, the rise in fibre content and the running-off in digestibility and feeding value that take place as the crop passes through the successive stages of growth up to flowering.

The cause of variation in the live-weight increase of animals on experiment has been further investigated. It had been shown previously that varying food intakes and initial weights-inherent drawbacks of the group-feeding method-accounted for much of this variation. When these two factors are rigidly controlled small differences in live-weight gains are still obtained. Evidence is presented to show that the basal metabolism and the digestive capacity of animals are for all purposes the same, and cannot account for any great part of the residual variation.

The application of a principle of “differential regression”, which is of value in the statistical treatment of some types of experimental data, is illustrated. Briefly stated, the principle involves the use of a separate regression coefficient for each subclass of observations when correcting these observations for the influence of variability in a correlated variate, instead of the use of an average net regression coefficient as employed in the usual variance and covariance analysis.

Attention has been drawn to the remarkable growth rates obtained in certain litters of pigs under farm conditions.

It has been pointed out that no explanation has been put forward to account for their occurrence.

The literature relating to the new dietary factor, physin (Mapson), essential for optimum growth and reproduction in experimental rats, trout and dogs, has been reviewed.

Experiments are reported in which rations, adequate as far as our present knowledge of essential dietary constituents goes, were fed to young growing swine. In each of three experiments, animals which received in addition 4 oz. of raw minced liver per day showed a 40 per cent. increase in growth rate compared with the controls.

When food intake was controlled according to the new method of individual feeding, the liver animals showed the same gains in weight as the animals receiving the basal diet alone.

1. The details of the Dennstedt dry-combustion method for determining carbon in soils were described, and some simplifications suggested.

2. The Bangor modified Kjeldahl method for carbon and nitrogen in soils requires carefully standardised heating. Errors may arise from contamination of sandy soils by material abraded during grinding in iron or porcelain mills.

3. For many heavy soils the addition of water before the Kjeldahl digestion is convenient but not essential. For heavy alkaline soils with little organic matter it is advisable to grind the soil very finely and to add water.

1. The shape or surface form of garden and field peas may be smooth, wrinkled or dimpled, depending upon the genetic constitution. The appearance of these forms is discussed and some comments made on the manner in which the characters are transmitted and expressed.

2. The genetic formulae of the three forms as suggested by other investigators do not explain satisfactorily the results observed from numerous crossings effected by the writers.

3. The following alternative combinations are offered as forming the constitution of the commercial varieties utilised:

1. Attention is drawn to the remarkable dissimilarity between the cacao and the grapefruit tree in their nutrient requirements, indicating that grapefruit is calcicolous in physiological habit. This conclusion is mainly based on a consideration of the results of chemical analysis of representative leaf material produced by trees grown on soil of known chemical and physical characteristics, under the same climatic conditions in Trinidad.

2. The nutrient relationships that obtain between the cacao and the grapefruit tree respectively and the soil in which they are growing have been gauged by means of chemical analysis of representative leaf material.

3. For this purpose, leaf material was obtained from trees growing on the differently manured plots of two large-scale field experiments in Trinidad.