The relation between moisture content and moulding in cured hay.
Samples of cured hay have been stored in closed containers at relative humidities of 0–95% at temperatures varying from 5 to 25° C. A curve relating equilibrium moisture content to relative humidity of the store has been constructed and the incidence of first mould growth noted. An explanation has been suggested to account for the apparent discrepancy between earlier published work concerning the onset of moulding and conditions normally prevailing on the farm. In laboratory storage experiments temperature conditions are relatively constant, whereas with hay stacked in the open air the high atmospheric humidity in winter is offset by a lowered temperature, and the higher summer temperature is accompanied by a lower moisture content in the hay.
Mould deterioration of feeding-stuffs in relation to humidity of storage: Part II. The water uptake of feeding-stuffs at different humidities
The water uptake of a wide variety of feeding-stuffs was determined over a range of fixed humidities. It was shown that the level and shape of the water uptake curves are closely related to the amounts of soluble carbohydrate and protein present. Fibre exerts a depressing effect on the water uptake, while the value is also lowered by the presence of inert fats and non-hygroscopic ash constituents. These conclusions were confirmed by direct experiments on the water uptake of samples of pure starch, protein and fibre. 
 
 
 
The results of the investigations have enabled safe limits of moisture content to be laid down, for both short- and long-period storage, below which mould growth will not normally take place. These limits vary for each individual feed, representative figures being included in the paper in tabular form.
Studies of the Growth of Moulds.--I
It is a remarkable fact that in the whole range of botanical literature there are so few references to the influence of humidity on the rate of plant growth. And this not because tire significance of humidity has passed unnoticed, for those botanists who during the latter half of the past century were tracing the history of the passage of plants from an aquatic to a sub-aerial environment were fully aware that the loss of water from the plant to the atmosphere was a factor whose influence could not be neglected. Both in their writing and investigation there is a constant attempt to explain how, by an increasing adaptation of plant structure and methods of reproduction, the difficulties of the loss of water to the atmosphere have been progressively overcome and growth in habits with a minimum of water has been finally attained. Experimental methods have been Used in the study of transpiration and much is known of its relation to relative humidity and other external factor. But even here much of the work has been primarily an attempt to prove how admirally leaves are adapted to withstand excessive water losses and how the so-called xerophytic characters still further reduce these losses. It is only quite recently that this bias has been overcome and that direct measurements of actual water Iosses have been made, that the rate of loss has been correlated with some of the many external factors influencing the process, and that a purely physical explanation has been advanced and not one based on the presupposed needs of the plant.