Abstract
When the green parts of living plants are cut up and packed in a loosely covered vessel allowing entrance of air, mould soon makes its appearance and decomposition begins: the mass becomes alkaline and is ultimately converted into black humic bodies quite unfit for cattle food. But if air is excluded the change is fundamentally different; no mould developes, the temperature rises, the mass takes on a greenishbrown colour and characteristic odour, it becomes acid and for a long period is suitable for cattle food. The former is a putrefactive change, the latter gives rise to silage.