esumed with the view of
artificially increasing the differentiation of the two main groups of
carbohydrates. From a portion of a barley crop the inflorescence was
removed as soon as it appeared. The crop was allowed to mature, and a
full comparison instituted between the products of normal and abnormal
growth. With a considerable difference in 'permanent tissue' (13 p.ct.
less) and a still greater defect in cellulose (24 p.ct.), the constants
for the furfuroids in relation to total carbohydrates were unaffected by
the arrested development. This was also true of the behaviour of the
hydrolysed extracts (acid processes) to yeast fermentation.

(5) The extract obtained from the brewers' grains by the process
described in (2) was investigated in relation to animal digestion. It
has been now generally established that the furfuroids as constituents
of fodder plants are digested and assimilated in large proportion in
passing through animal digestive tracts, and in this respect behave
differently from the pentoses. The furfuroids being obtained, as
described, in a fully hydrolysed condition (monoses) the digestion
problem presented itself in a new aspect, and was therefore attacked.

The result of the comparative feeding experiments upon rabbits was to
show that in this previously hydrolysed form the furfuroids are almost
entirely digested and assimilated, no pentoses, moreover, appearing in
the urine.

Generally we may sum up the present solution of the problem of the
relationship of the furfuroids to plant assimilation and growth as
follows:--The pentoses are not produced as such in the process of
assimilation; but furfural-yielding carbohydrates are produced directly
and in approximately constant ratio to the total carbohydrates; they are
mainly located in the permanent tissue; in the secondary changes of
dehydration, &c., accompanying maturation they undergo such
differentiation that they become readily separable by processes of acid
hydrolysis from the more resistant normal celluloses; but in relation to
alkaline treatments they maintain their intimate union with the latter.
They are finally converted into pentoses by artificial treatments, and
into pentosanes in the plant, with loss of 1 C atom in an oxidised form.
The mechanism of this transformation of hexoses into pentoses is not
cleared up. It is independent of external conditions, e.g.
fertilisation and atmospheric oxidations, and is probably therefore a
process