In Table XII is given a summary of the mean digestion coefficients obtained in the foregoing maize feeding experiments.

The figures in Table XII bring out very clearly the effect of preliminary treatment on the digestibility of maize. An inspection of the dry matter digestion coefficients reveals the fact that maize meal possesses the lowest digestibility when fed in the dry condition, a higher value when fed after thorough soaking in water and a higher value still when first submitted to cooking.

These facts are in accordance with anticipation; the surprising feature of the results, however, lies in the discovery of the inappreciable extent to which the maize digestibility is raised by soaking or cooking. A relatively low degree of digestibility might justifiably have been anticipated for raw unsoaked maize, since the hard flinty nature of the grain, even after crushing, might render it liable to be excreted in appreciable amount into the faeces without having been much affected by digestive enzymes. This proved by no means to be the case. The effect of thoroughly soaking the grain prior to feeding was merely to raise the digestibility of the maize by 1 per cent, (from 85·9 per cent, to 86·9 per cent.), whilst even efficient cooking only brought about a rise in digestibility from 85·9 to 88·1 per cent., although, as will be noted by reference to an earlier part of this communication, the conditions of the trial were weighted in favour of the cooked meal by using fine meal for cooking and crushed maize for dry-feeding.

In the foregoing communication on maize digestibility (i), reference has already been made to the early difficulties which arose as a consequence of attempting to make measurements on rations consisting wholly of maize and milk. During, the period in which a mixture of milk and flaked maize was being fed, the pigs developed constipation troubles, due, as subsequent results proved, to the almost complete digestion and assimilation of the ration by the animals. At the time, however, it was deemed expedient to alter somewhat the scheme of the experiment and to feed the maize along with a definite weight of coarse middlings. In this manner it was anticipated that the fibre of the coarse wheat offal would promote peristaltic activity in the intestinal tract and thus assist the passage of undigested food residues.

The introduction of the middlings into the experimental ration made necessary the determination of the digestibility of this feeding stuff. The results of this trial are given for convenience in this separate communication.

During the investigation in connection with maize digestibility recorded in the current issue of this journal (1), a period of feeding was carried out in which the two pigs received a ration consisting of unsoaked crushed maize and whole milk. Although it was found necessary to discontinue the main maize trial along these lines, the results of this isolated period are not without interest, since they enable conclusions to be drawn concerning the extent of the digestion and assimilation of the constituents of milk when fed to swine.

The crushed maize used in this period was from the same stock as that fed in the mixed maize and middlings periods. The daily ration consisted of 2000 gm. crushed maize together with one quart of whole milk; it was given in two equal portions during the day, the milk and a little water being mixed with the dry maize in the trough at the time of feeding. The presence of the milk appeared to make the ration attractive to the animals, since ready and complete consumption was obtained.

(1) Hydrogen peroxide oxidises or renders soluble a portion of the organic matter of soils. It appears to be without action on fibrous organic substances such as cellulose and lignins. Humified material seems to be oxidised completely or brought into a water soluble state.

(2) Treatment with hydrogen peroxide is proposed as the basis of a method for estimating the approximate degree of humification of soil organic matter.

(3) Among the soils examined, the highest degree of humification is found in peats and uncultivated soils. It is possible that the degree of humification is correlated with the prevalence of anaerobic conditions.

(1) Rather over 50 per cent, of the cows in this country probably possess accessory or supernumerary teats, the number of which varies from one to three.

(2) In many cases at any rate, these teats are associated with additional glands.

(3) These additional glands are frequently functional and secrete milk.

(4) Ordinarily this milk is absorbed into the circulation, the lactose being secreted in the urine.

(5) The presence of active accessory or supernumerary glands is an undesirable characteristic since it involves the formation of milk which is not utilised.

(1) The relationship between phosphate soluble in 2 per cent, citric acid and total phosphate present has been investigated in the following cases:

(a) Phosphates of known composition.

(b) Basic Slags.

(c) Mineral Phosphates.

(2) The relationship is best shown graphically and in nearly all the above cases is a straight line passing through the origin.

For each of three basic slags of widely differing citric solubility, the graphis a straight line showing that citric solubility is a definite constant, independent of the weight taken in the test, when allowance is made for a small constant error in the determination.

(3) The ratio soluble phosphate/total phosphate in the case of the mineral phosphates Gafsa, Ephos, Nauru, and a West Indian phosphate, depends on the weight taken in the test, the graphs are not straight lines.

Attention is drawn to the fact that there is variation, both morphological and physiological, within the aggregate of plants known as “white clover.” After a detailed study of some of the characters of the plant, it has been determined which of these are constant and which are alterable by external conditions.

The cyanogenetic behaviour has not been found correlated with any recognizable external feature of the plant, and has been found constant from year to year, and under different soil conditions. For this purpose, separate plants grown in pots and “clone” plants on various soils were used.

As a result of the study of distribution of cyanogenetic and acyanogenetic forms of white clover, it has been found that “positive” or “negative” plants give rise, under “open” conditions of pollination, to offspring approximately 75 per cent, of which are possessed of like cyanogenetic character.

Much of the modern work on the physical properties of soil has been interpreted on a colloidal basis and more recently this hypothesis has been extended by the thermodynamical studies of Wilsdon and also by the investigations of two of us on an indirect measurement of the vapour pressure of capillary systems. There is evidence that the colloidal portion of the soil can be regarded as possessing a reticulate structure, possibly analogous to that shown by Zsigmondy to exist in silica gels. The pore space in soils is therefore an assemblage of voids and irregular capillaries ranging from ultramicroscopic dimensions in the colloidal portions to the macroscopic interstices between adjacent compound particles and the larger mineral fragments. Whereas in studies of evaporation and movement of water the total intersticial space is operative, the vapour pressure of soils at different moisture contents is very largely controlled by the minute pores associated with the colloidal portion and the larger voids have comparatively little influence. Vapour pressure measurements therefore afford a promising line of attack on the physical relations between the colloidal soil material and water, especially when the measurements are made on soils subjected to a variety of preliminary treatments, known to have a considerable effect on other physical properties. The effect of successive wetting and drying, heating and addition of salts are of especial interest in this connection.

It has long been recognised that in plants the susceptibility to disease is influenced to a considerable extent by the manuring practice followed. Ill-balanced fertiliser mixtures decrease the capacity for disease resistance; this has been frequently observed after the application of excessive amounts of nitrogenous manures, and has been demonstrated at Rothamsted and Woburn, where wheat and barley suffered most severely from rust and mildew in those plots which received excessive quantities of nitrogen; also at Cheshunt, where tomatoes heavily dressed with nitrogenous manures were readily attacked by disease-producing organisms. The effect of applying phosphoric acid has not, apparently, been clearly demonstrated, but it is generally assumed that, by favouring the development of a vigorous root system, its action is beneficial. Experiments at Cheshunt have shown that the use of manures from which potash has been omitted, produced a condition similar to that following the application of excessive amounts of nitrogenous fertiliser, and that the addition of potash tends to increase appreciably the ability of the plant to resist disease.

1. The value of lime-sulphur, liver of sulphur and ammonium polysulphide depending upon the amount of polysulphides that they contain, there is need for an exact method for the estimation of their content of polysulphide sulphur.

2. The method of R. M. Chapin has been tested under a variety of conditions and, after making slight modifications to increase rapidity and ease of manipulation, it is recommended as being sufficiently accurate for the purpose in view.