and, in
light, sandy, and well-drained soils, and in warm and dry districts,
the mildew is a rare visitant. The "blue mould" (_Aspergillis glaucus_)
attacks hay and straw in the stack or rick, and without any regard to
their origin--no matter whether they were the produce of the wettest or
the dryest, the warmest or the coldest of soils. The chief condition
in the existence of the blue mould is excessive moisture. If the hay or
straw be too green and succulent when put up, or if rain get at them
in the rick, the mould is very likely to make its appearance, and the
well-known odor termed _musty_ will speedily be developed.

Neither the mildew nor the mould can, strictly speaking, be regarded as
parasites, such as, for example, the flax-dodder, which feeds upon the
healthy juices of the plant to which it is attached. It appears to me
that the tissues and juices of the fodder-plants decay _first_, and then
the mould or the mildew appears and feeds upon the decomposing matter.
Now, as these vegetables belong to a poisonous class of fungi, it is
more than probable that they convert the decomposing substance of the
straw or hay into unwholesome, if not poisonous matter; and it is not
unlikely but that the disagreeable odor which they evolve is designed by
nature as a sign to the lower animals not to partake of mouldy food.
There is no doubt but that most animals will instinctively reject fodder
in this state; and the question arises, ought this odour to be destroyed
or disguised, in order to induce the animals to eat the damaged stuff?
The experience of most feeders who have largely consumed mouldy provender
is, that although cattle may be induced to eat it, they never thrive
upon such stuff if it form a heavy item in their diet. The reason of
this is obvious. The nitrogenous portion of the straw is that which is
chiefly assimilated by the fungi. And as this constituent is the one
which contributes to the formation of muscle, and is naturally extremely
deficient in straw and hay--more particularly the former--it follows
that the animals fed upon mouldy fodder cannot elaborate it into lean
flesh (muscle).

In the case of young stock, mouldy fodder is altogether inadmissible,
for these animals require abundance of flesh-forming materials--precisely
those which the fungi almost completely remove from the diseased fodder.

As large quantities of mouldy or mildewed provender are at the present
moment to be found in many farmstea