1. Monthly aqueous extracts of soils which have been under wheat and barley cropping on the Woburn light sandy loam soils, with various manuring show very great similarity in the amount and character of the materials extracted in the wheat and the barley soils.

2. Water-soluble phosphoric acid and potash are in extremely small amount where these manures have not been applied during the fifty years’ treatment, but, in spite of this, the amount of these constituents does not appear to be a limiting factor in determining the yield of either wheat or barley. The phosphoric acid is much higher in the plots treated with phosphatic manures, and the potash is slightly higher in those treated with potash manures, but these facts do not seem to have secured a seriously higher yield.

It is not intended to present a detailed summary of the many points arising out of this investigation. The following represents merely a brief statement of the field covered and the major features emerging.

1. Complete anatomical dissection of eleven wether lambs at approximately 4·5 months old and 40 lb. carcass weight and five wether hoggets at approximately 13 months and 60 lb. carcass weight provided material for a comparative study of the anatomical composition and characters of different breeds and crosses of which the individuals concerned were selected as representative.

2. In both lambs and hoggets this study confirms the picture presented by the statistical comparison based on carcass measurements of the same breeds and crosses at constant weight described and discussed in Part II.

3. The breed differences in the relative development of the different regions of the body and the relative development of the major tissues, bone, muscle and fat in different joints and the total carcass have been studied in relation to carcass quality.

4. From the differential development of the different parts and tissues of the body in the various breeds and crosses, the concept of early and late development as a fundamental factor in meat production is demonstrated.

5. The proportional development of the various parts of the body and its major tissues in lambs and hoggets is compared. Regions of an intermediate rate of development are relatively best developed in the hoggets. In the total carcass, bone has increased least, muscle only slightly more and fat most, with an increase in age from 4·5 to 13 months and body weight from 40 to 60 lb. This is in line with the order of the development of the tissues.

6. The differential effect upon differentially developing tissues of the plane of nutrition is advanced as a major factor influencing the relative differences between lambs and hoggets.

7. Variations, affecting the value of the animal for meat production, in the number of vertebrae in the different anatomical regions have been described.

8. The bearing of the many factors discussed and principles elucidated upon practical problems of lamb and mutton production has been considered.

It is impracticable to give a detailed summary of the many findings of.this experiment; attention is confined, therefore, to the major aspects and the general principles emerging.

1. By quantitative control of the plane of nutrition, twenty closely inbred pigs have been made to conform to four major variations in the shape of the growth curve from birth to 200 lb. live weight. A high rate throughout (High-High), a high followed by a low rate (High-Low), a low followed by a high rate (Low-High) and a low rate throughout the period (Low-Low) afforded comparison between animals of the same weight but different age and between animals of the same weight and age but with differently shaped growth curves. The relative effects of the treatments upon the development of body proportions and anatomical composition have been studied.

1. An account has been given of the percentages of nutrients in the dry matter and weights of nutrients in tops, tubers and roots of potato plants throughout growth under six fertilizer treatments.

2. Manurial treatment affected dry-matter content of tops but not of tubers.

3. Balanced manuring, as represented by N2PK treatment, resulted in tubers in which nitrogen content of dry matter declined with age. The effect of the K was to lower the nitrogen, phosphorus and calcium contents, to increase chlorine content of all parts of the plant, and to maintain a much higher and more constant concentration of potassium in tops and roots. With unbalanced manuring the nitrogen content of the tubers was more constant.

4. Manuring with nitrogen only raised the content of potassium in the dry matter of all parts of the plant.

5. Nitrogenous manuring, whether alone or in combination, raised the nitrogen content of the dry matter of all parts of the plant, a smaller proportion of which was present as protein. Calcium and chlorine contents were lowered.

6. Phosphate manuring in conjunction with nitrogen depressed the concentration of potash in the dry matter of all parts of the plant.

7. N2P plants were the first to attain their maximum uptake of all nutrients, namely, about 7 weeks from appearance above ground, at which time N2PK plants had absorbed only 40% of the quantities finally noted.

8. No losses of elements were observed in the plants which received balanced manuring (N2PK), but losses of calcium and chlorine occurred in all other plants, amounting on the average to 25 and 37% respectively, but being highest in N2P plants. A significant loss of potassium occurred in N2 plants and a highly suggestive loss of phosphorus occurred in N2P plants.

The present investigation is the sequel to an earlier pig-feeding trial in which a diet supplying only half the standard amounts of protein supplement, in the form of a mixture of feeding blood meal, dried separated milk and ex. soya bean meal, was found to give as good results from the standpoints of rate of growth, efficiency of food conversion and carcass leanness and quality, as a diet that contained the full standard allowances.

It was considered desirable to repeat this initial exploratory experiment, making use this time of a totally different form of protein supplement, since the question of the biological efficiency of the protein supply might conceivably be of critical importance at the lower levels of protein feeding. In the present trial, therefore, the mixture of the three protein foods was replaced by a single protein food, namely, white fish meal. The standard-protein treatment C supplied 12% of white fish meal up to 90 lb. live-weight, 10% from 90 to 150 lb., whilst from 150 lb. to slaughter at about 200 lb. live-weight, the white fish meal was omitted from the diet, its place being taken by 5% of ex. soya bean meal. The corresponding allowances of protein food in the low-protein treatment B were 5, 4 and 3% respectively. The low-protein treatment A, which was introduced as a link between the previous and the present trials, contained the protein supplement composed of feeding blood meal, dried separated milk and ex. soya bean meal and supplied the same amount of digestible protein as was contained in the low-protein treatment B.

Apparatus for measuring the rate of diffusion of carbon dioxide through granular solids is described and the results obtained with it are shown to conform to the curve connecting D/D0 and S previously obtained for carbon disulphide and acetone. The equation D/D0 = 0·66S, which it is suggested should replace Buckingham's equation D/D0=S2, is applied to a discussion of soil aeration, and it is shown that at all porosities the rate of diffusion of carbon dioxide from the soil is sufficient to account for normal respiration without invoking the assistance of meteorological changes. A further application of the equation to water vapour movement in soils is briefly discussed.

As a result of one detailed experiment and four demonstrations carried out on the University Farm at Cambridge the following conclusions can be drawn:

1. Lucerne drilled at a constant seed rate per acre, in narrow rows (3½ and 7 in.), gave a greater yield per acre than when drilled in rows 10½ and 14 in. in width. Over a four-year period the yield of dry matter per acre from narrow rows was half a ton more than from wide rows. No evidence was obtained that weed infestation is reduced by narrow drilling.

2. The broadcasting of 5 lb. of trefoil per acre at the time the lucerne was drilled had no effect on the total yield or on weed infestation.

3. Wild white clover broadcast at the rate of 2 lb. per acre at the time of drilling the lucerne slightly reduced the yield of lucerne in the first harvest year, but subsequently it served to secure some control of weeds, and thereby favoured the persistence of the lucerne. Differences in yield associated with sowing wild white clover were, however, slight.

4. Commercial cocksfoot broadcast at the rate of 10 lb. per acre at the time of drilling the lucerne led to very considerable increases in total yield (nearly 3 tons per acre of dry matter over a four-year period). The increments were obtained principally during the spring growth, and some loss of lucerne plants was suffered, so that in a very dry summer the total aftermath yield was slightly reduced. Since cocksfoot almost completely controlled weeds and its mixture with lucerne was very suitable for hay or for silage, it is regarded as a plant that may be included in a lucerne ley with advantage.

No attempt will be made to give a detailed summary of all the findings of the present experiment. It is rather our purpose to draw attention to the main principles emerging.

1. The influence of extremes of high and low planes of nutrition during the first 16 weeks of post-natal life upon the growth in body proportions and in anatomical composition has been studied experimentally in six pairs of closely inbred pigs. Quantitative differences in nutrition operative from birth have resulted in an average live weight at 16 weeks of 113 lb. in the High-Plane and 37 lb. in the Low-Plane animals.

2. In body proportions, the head, ears, neck, legs, and body length are penalized relatively less by inadequate nutrition than are body depth, loin, and hindquarters. Conversely, good nutrition favours most the latter characters. These effects upon body form are similarly evident i n the gross weight of the different anatomical regions involved. Low-Plane animals to a large extent retain the proportions of the juvenile and High-Plane approach the conformation of the adult

The dependence of the coefficient of diffusion, D, upon the porosity, S, of a granular solid is investigated experimentally. For steady state conditions, using carbon disulphide and acetone vapours, it is shown that a curve connecting D/D0 and S can be drawn which is independent of the nature of the solid, its moisture content and, within limits, its texture. For a limited range of values of S (0·0 < S < 0·7) a good approximation is D/D0 = 0·66S and over this range the diffusion coefficients are larger than those found by Buckingham for carbon dioxide.

Investigation of the non-steady state shows that in soils the attainment of pressure equilibrium is retarded by adsorption, and it is suggested that Buckingham's low values for steady-state conditions can be attributed to premature observations of the diffusion rates; the steady state had probably not been attained when his measurements were made.

Attention is directed in this paper to the desirability, particularly at the present time, of conserving, for purposes of winter-feeding, the pea-pods that accumulate in large quantities at the factories during the pea-canning season. Conservation on the farm is best carried out by the method of ensilage, young pea-pods, such as are obtained in the factory, giving rise to a very satisfactory type of silage without the use of molasses. Broad-bean-pods, on the other hand, do not lend themselves to successful conservation by ensilage, owing to the fact that they become “slimy” in the process and yield an unpalatable product.

Both pea-pods and bean-pods are conserved in the factory by the method of artificial-drying. One such process is described in the present paper. The final product in both cases is obtained as a fine brown meal. Pea-pod meal, in some respects, particularly in regard to its satisfactory content of protein and lime, has a composition not unlike that of the leguminous hays. The similarity, however, does not extend to the fibrous constituent, pea-pod meal having a very much lower fibre content than the hays.

An outstanding characteristic of pea-pod meal is its richness in sugar, no less than 16·5% of the dry matter consisting of a mixture of sucrose and invert sugar. It is the presence of this abundance of sugar that accounts for the favourable fermentation that takes place when young pea-pods in the fresh condition are conserved as silage.

Bean-pod meal displays the same general features in respect of composition, but is distinctly poorer in lime and sugar than the pea-pod meal. Pea-pods and bean-pods, both in the fresh and artificially-dried condition, contain very little carotene and have, therefore, little or no significance as a source of this vitamin A-precursor in the feeding of live-stock.

1. An examination of carcass reports from two groups of bacon pigs (comprising eleven litters and seventy-five pigs) was made to determine whether the variation in growth rate of normally reared pigs was associated with differences in carcass measurements. The method adopted was to fit orthogonal polynomials to the third degree to the last 10–11 fortnightly weighings converted to logarithms.

2. The residual standard deviation after fitting was about 2–4%. For present purposes, the fitting of second degree parabolae appeared adequate.

1. For both genetical and methodological reasons, tests for quality, in the majority of breeding schemes, are not required at the early stages of the breeding process.

2. Reliability and definition of any one empirical test is not sufficient to safeguard against losses of valuable material.

3. It is suggested, therefore, that as a rule agronomically promising lines should be carried on to a stage where comprehensive tests, using a number of selected methods, can be carried out, preferably over a number of seasons. It may be questioned whether a combination of such tests as the wholemeal fermentation and the gluten swelling tests (Pelshenke, 1938a) would suffice. In the light of the available evidence a testing system might be suggested comprising baking tests together with such “indirect” and, better still, “analytical” methods as will afford accurate information of an analytical nature.

4. This review of the testing problem suggests the conclusion that empirical tests are limited in their significance and reliability, and that only an increased knowledge of the fundamentals can afford a truly scientific approach. It should be admitted that the plant breeder, with his insistence on empirical tests where fundamental knowledge was lacking, has side-tracked the cereal chemist from the narrow path of scientific approach all too often. It is questionable whether this has been to the ultimate advantage of wheat breeding.

5. Inheritance studies on quality should greatly facilitate the task of the breeder. They will become feasible and valuable only when the nature of the desirable characters and the true significance of the testing methods are clearly understood.

The results are described of twenty-two experiments carried out on the feeding of bacon pigs at different centres throughout Great Britain, in the course of which nearly 400 pigs were fed according to three different scales of rationing. All the pigs were fed on the same scale until reaching 100 lb. live weight, when they were eating 4 lb. of meal per head per day. From this stage three different levels of feeding were followed; in each case the daily allowance reached a maximum when the pigs were 170 lb. live weight. The amounts being fed were then: 7 lb. 8 oz., 6 lb. 5 oz. and 5 lb. 3 oz. per head per day respectively.

1. Phytic acid in cereals and in certain rations based on cereals was incompletely hydrolysed during its passage through the intestinal tract of the pullet.

2. The percentage recovery in the droppings of phytic acid in a ration (24·2%) based on cereals plus extracted soya bean meal was considerable even when the ration included no calcium supplements. Both calcium carbonate and tricalcic phosphate greatly increased the percentage recovery. A supplement of calcium carbonate led to a somewhat higher recovery of phytic acid than a supplement of tricalcic phosphate containing the same amount of calcium.

3. The recovery of phytic acid tended to be somewhat higher in laying birds than in non-laying birds; this may have been associated with decreased amounts of calcium in the alimentary tract due to the demands for egg-shell formation.

4. The observations of Knowles et al. on the composition of the droppings of non-laying pullets on certain rations were confirmed; it was found, however, that their rule connecting the amounts of carbonate, calcium and phosphorus in such droppings did not extend (a) to the case of laying pullets, or (b) to certain other rations of wider Ca/P ratio.

5. The interpretation of the rule enunciated by Knowles et al. to mean that calcium and phosphorus are normally excreted by the pullet as dicalcium phosphate and calcium carbonate was shown to be untenable in view of the fact that the droppings may obey this rule and yet contain considerable amounts of phosphorus in organic combination.

1. Individual birds have a characteristic date for the termination of the egg laying cycle.

2. The date of cessation of production at the end of the pullet year is not a reliable indication of the bird's potentiality in this respect.

3. The longer the birds are retained the greater is the chance of distinguishing the true date.

4. Individual dates for the termination of the cycle occur at so many points throughout the total range (from July to December) that this must either indicate a multiple factor situation or that the genes involved show a considerable range of expression.

1. The comparative nett energy for fattening of Sussex ground oats and white maize meal have been determined on Light Sussex cockerels by difference experiments with a direct calorimeter.

2. The mean values for nett energy per gram dry matter, nett energy/ metabolizable energy, metabolizable energy per gross feed energy and digestible energy per gross feed energy were as follows:

3. There was no significant difference in the utilization of metabolizable energy from the two cereals. The higher nett energy of the white maize meal was due to its higher digestibility.

We again welcome the opportunity of expressing our indebtedness to Mr G. A. Childs for his assistance in carrying out the experiments.

1. It is possible to determine the size distribution of clods in the field by simple sieving of the soil without any pre-treatment provided the soil is not too wet. There is a personal factor involved in the sieving, but with care and training this will not affect comparisons of results obtained by that person. If the soil is too wet the individual clods smaller than 3 mm. stick together on the 3 mm. sieve. This sticking together is first apparent on the 3 mm. sieve but may become appreciable on the ¼ in. (6 mm.) sieve. No certain way was found for overcoming this difficulty.

2. There appears to be no best method for determining the size distribution of the soil crumbs, i.e. of the water-stable aggregates in the soil. The method and the technique must be chosen so as to give the maximum amount of useful information. If an appreciable proportion of the crumbs are larger than ½ mm., a water-sieving method is practically essential.

3. The method of wetting to be used can only be chosen from a consideration of what information is wanted. If possible it would be desirable for general purposes to use a very slow or a vacuum wetting technique and a very rapid wetting technique such as wetting the soil by immersion in water.

4. The decision whether air-dry or field-moist soil should be used depends entirely on the information needed. For general purposes the use of air-dry soil is recommended.

1. An outline of recent investigations on the cause of marsh spot in pea seeds indicates that the disease is caused by a deficiency of available manganese in the soil.

2. The symptoms of the disease are very briefly described.

3. The methods of analysis used by the writers for determining the amounts of manganese in whole peas and in different parts of peas are described.

4. As no loss of manganese was found to result from soaking the peas in water for 24 hr., soaked peas were used for dissection in preference to dry peas.

5. Referring to the diseased peas, the highest level of manganese was found in the peripheral tissues of the cotyledons, followed by the germ and seed-coat. Only slight traces of manganese were found in the healthy and in the necrotic tissue from the centre of the cotyledons. All parts of the healthy seed were richer in manganese than the corresponding parts of the diseased sample. In addition, the order of distribution was different; notably in that the tissue from the centre of the cotyledon contained a higher level than the seed-coat, and the germ a higher level than the outer layers of the cotyledon.

6. A given weight of small peas proved to contain less manganese than the same weight of large peas selected from the diseased sample. The reverse was found to be true for similar size groups selected from the healthy sample. These differences in the manganese content of size groups suggest that peas of uniform size should be selected for analysis when the relative manganese levels of different samples are to be tested.

7. It is suggested that migration of cell contents from the necrotic tissue of diseased peas may partly account for the differences in manganese content of healthy and diseased peas.

1. In the Eastern Counties of England, annual wastage from milk recorded dairy herds amounts to 29·3 % of the number of cows at the beginning of the year.

2. Average length of productive herd life in milk recorded herds is 3·4 years.

3. Average length of total productive life in milk recorded herds is probably a little more than 4 years. Average length of total productive life in all herds is probably longer, and may be of the order of 5 years.

4. Deaths of cows are equivalent to 10·4% of the total wastage, and to a mortality rate of 3·0% of the number of cows at the beginning of the year.

5. During the three-year period 1934–5 to 1936–7, cows leaving the herd realized an average of £10. 10s. 6d. per head. The average market value placed upon heifers when they entered the milking herd was £20. 14s. per head, while cows for replacement purposes cost an average of £22. 5s. per head.

6. Of all replacements, 67·7 % are heifers, but not all of these are home-bred. In annual valuations, 49·0 % of cows are described as homebred, 50·6% as purchased and 0·4% as unknown.

1. The influence of storage in the light and in the dark at ordinary temperature and in a heated room at 70–80° F. on the carotene content of finely ground artificially dried grass stored in paper sacks and jute sacks was studied. There was an initial drop in carotene content from 61·1 to 46·5 mg./100 g., i.e. 23·9%, in the first month, and a total loss of 31·4% during 6 months' storage (August to February). No difference could be detected either between treatments or types of containers.

2. There was a marked loss of carotene during 13 months' storage of baled artificially dried grass and of hays, amounting to 30–40% of the original value.

3. Two methods of estimating carotene were compared. The method of Ferguson & Bishop (1936) gave higher results than the method of Peterson, Hughes & Freéman (1937). The difference is probably due to incomplete extraction in the latter method.

4. Chromatographic analyses of “carotene” fractions from the above grasses showed the presence of coloured impurities amounting to 20·5–33·8% of the total recovered pigments.

5. As these impurities are biologically inactive, chromatographic analysis or the use of special solvents are probably necessary for the accurate determination of carotene in forage.