One of the difficulties which hinder the extended use of the nut-oil-cakes (palm kernel, coconut and ground-nut) is the prevalent impression that these cakes deteriorate rapidly on keeping. In recent articles dealing with these cakes frequent reference has been made to this point. Thus Voelcker (9) in his Annual Report for 1914 states that “one inconvenience attaching to palm-nut and coconut cakes is that they do not keep as well as linseed and cotton cakes and that there is a tendency for them to turn rancid.” In his Report for 1915, however, he says, “I have come across but few instances either with palm-nut cake or meal, in which these have been rancid or not in good condition.” Murray (8) states that manufacturers should realise that they still have to reassure farmers regarding the keeping qualities of palm kernel cake. In a later article in the Journal of the Board of Agriculture (3) it is stated that “palm-nut kernel cakes in the past have had the reputation of soon going rancid…. At the present day, before the kernels are crushed they are subjected to a process of cooking, by which the ferment that causes the oil to turn rancid is rendered inactive.” The validity of this latter assertion seems doubtful in the light of the recent work of Calder (2) which shows that the lipase, present in the resting seed in the form of its zymogen, is not destroyed during the manufacture of the cake, the mass of crushed kernels not being sufficiently heated in every part prior to pressing to secure this object completely. Similar statements have been made as to the liability of coconut and ground-nut cakes to become rancid on storing (3,4).

The interest aroused recently in the utilisation as feeding-stuffs of the residual cake or meal remaining from the extraction of oil from palm kernels has directed attention to the scantiness of our information as to the digestibility of these products. The average digestion-coefficients given in the commonly-used tables of Kellner are based in each case upon only three experiments with two different consignments of material, and showing in certain particulars a very wide range of variation in the individual results. With one exception, where an ox was used, these experiments were carried out with sheep and all date from the ’seventies of last century (1, 2).

At the close of the digestion experiments described in the foregoing communication a quantity of the “seeds” hay of known composition and digestibility remained which was sufficient for one further experimental period. The opportunity was therefore taken of determining the digestibility of dried yeast, a by-product of the fermentation industries which is being produced in increasing quantities and which has attracted notice since the outbreak of war.

The experiment described in the present communication was carried out at the Manor Farm, Garforth, during the summer of 1916, with the object of obtaining information as to the nature of any changes in the composition of milk-fat that might be effected by the feeding of palm kernel cake to cows.

In certain seasons very severe losses are caused to the hop-crop by the depredations of the mildew Sphaerotheca Humuli (DC.) Burr. Among hop-growers in England this mildew is commonly spoken of as “mould” when it occurs on the leaves or the female inflorescences (“burr”) of the hop-plant, and as “red mould” when it attacks the stipular bracts and bracteoles of the strobiles (“hops”) (1).

A Short preliminary note on this disease was published Nov. 1912(4), and since that date further investigations have been carried out into the life-history of the organism, and its effect on the host plant. As 1 there showed the disease is caused by a bacterium for which I propose the name Pseudomonas seminum.

The organism which produces “Blackleg” of the potato in Lancashire is B. atrosepticus (van Hall).

It is in all respects identical with the organism responsible for this disease in Ireland and described by Pethybridge and Murphy under the name B. melanogenes.

We can now bring together the various results obtained during the course of our investigations.

We find that the changes are at a minimum under anaerobic conditions, and they are as follows:

1. In the laboratory experiments as much as 17 % of the dry matter may be converted into gas: in the heap the proportion is less.

2. The non-nitrogenous constituents are particularly affected, as much as one quarter of the pentosans may disappear during the process and other constituents break down in like proportion. The gas evolved contains carbon dioxide, marsh gas, and hydrogen.