The present investigation was undertaken to study the decomposition of cyanamide and dicyanodiamide in the soil and their specific action on plant growth. Their close chemical relationship necessitated a comparison of their respective behaviour in the soil. Dicyanodiamide is a polymer of cyanamide to which the formula C2H4N4 is assigned. Morrell and Burgen(1) and Werner (2) have shown that the polymerisation is caused by acids or alkalis, even in small amount, but a weak alkali is substantially more effective than a correspondingly weak acid; the rate of the change is greatly increased by raising the temperature. The process does not appear to be reversible.

With the great increase in the use of palm kernel cake, which has taken place in this country in the last few years, attention has been drawn to the rancidity which the cake is liable to develop under certain conditions. R. B. Calder (see this Journal, April, 1916, VII, 470) has shown that the cake develops rancidity under sterile conditions and concludes that the action is due to the presence of a lipase. Calder has taken as his criteria of rancidity a sour smell in some cases and an acid reaction with litmus in others. There is some confusion in the use of the terms “rancidity” and “ acidity.” Although rancidity stands in close relationship to acidity and invariably accompanies a high acidity in oils and oil cakes, the terms are not synonymous.

From the foregoing account the following summary may be given:

1. Examination of Rothamsted soils on different occasions has revealed the presence of an organism capable of breaking down cellulose with comparative ease.

2. This organism presents a number of features of morphological and physiological interest. Morphologically, the organism appears to possess greater affinities with the Spirochaetoideae than with the bacteria and the name Spirochaeta cytophaga is, therefore, suggested.

3. While the spirochaet is capable of considerable vegetative growth as a sinuous filamentous cell, it also appears to pass through a number of phases which terminate in the production of a spherical body (sporoid) which differs in a number of respects from the true spores of the bacteria. Germination of the sporoid again gives rise to the filamentous form, which possesses perfect flexibility and is feebly motile. The latter does not apparently possess flagella.

4. Spirochaeta cytophaga is essentially aerobic; its optimum temperature is in the region of 30°. Both the thread and sporoid stages are killed by exposure to a temperature of 60° for ten minutes.

5. The nitrogen requirements of the organism may be met by a number of the simpler nitrogen compounds—ammonium salts, nitrates, amides and amino-acids. Peptone is also suitable in concentrations up to 0.025 per cent. Stronger solutions, e.g. 0.25 per cent., lead to marked inhibition of growth. The organism fails to grow on the conventional nutrient gelatine or agar.

For purposes of discussion of the problems of meat production the term “condition” may be defined as the ratio of the amount of fat to the amount of non-fatty matter in the body of the living animal, and the term “fattening” as any alteration in this ratio. Such alteration may result from (a) increase, (b) decrease in the amount of fat, (c) increase, (d) decrease in the amount of non-fatty matter. This, of course, implies that fattening may be either positive or negative and that the “increase” may be mathematically a minus quantity.

It is now accepted as a fundamental doctrine in animal nutrition that the prime function of food is to supply energy for the operation of the human or animal body and that all its other diverse uses are essentially tributary to this main purpose. The growing recognition of this fact in its relations to the nutrition of farm animals has given rise during the past twenty-five years to extensive investigations, especially by Zuntz and his associates, by Kellner and Köhler and by the writers, in which the attempt has been made to determine experimentally how much energy the various feeding stuffs can actually contribute toward the upkeep of the animal body.