stitutional
nitrogen. When hydrolysed these fungoid celluloses yield, in addition to
monoses, glucosamine and acetic acid. The celluloses of the phanerogams
are generally associated, in a degree ranging from physical mixture to
chemical union, with other complicated substances, constituting the
"compound celluloses." The nature of the associated groups affords a
convenient classification into pecto-celluloses, ligno-celluloses and
cuto-celluloses. _Pecto-celluloses_ are so named because the associated
substances--carbohydrates, together with their oxidation products, i.e.
containing either two carbonyls (CO) in the unit group or carboxyl (CO.OH)
groups in a complex--are readily hydrolysed by weak acids to the
gelatinous "pectic acids" or their salts. _Ligno-celluloses_ are the
substances of lignified tissue, the non-cellulose constituents of which
are characterized by the presence of benzenoid and furfuroid groups; and
although essentially complex, they may be regarded as homogeneous, and are
conveniently grouped under the name _lignone_. The lignone complex reacts,
by its unsaturated groups, with the halogens. It is a complex containing
but little hydroxyl; and is of relatively high carbon percentage
(55.0-57.0%). _Cuto-celluloses_ predominate in the protective coatings of
plant organs, and are characterized by constituent groups, the
decomposition products of which are compounds of the fatty series, and
also wax alcohols, acids, cholesterols, &c.

The typical pecto-cellulose is the flax fibre, i.e. the bast fibre of
the flax plant (_Linum usitatissimum_), as it occurs in the plant, or as
the commercial textile fibre in its raw state. Rhea, or ramie, is
another leading textile fibre in which the cellulose occurs associated
with alkali-soluble colloidal carbohydrates. Pecto-celluloses are found
in the stems of the Gramineae (cereal straws, esparto), and in the
fibro-vascular bundles of monocotyledons used as textile and rope-making
fibres. They are the chief constituents of the fleshy parenchyma of
fruits, tubers, rhizomes. Ligno-celluloses find their chemical
representative in the jute fibre. They constitute the woods, and are
therefore of the widest distribution and the highest industrial utility.
It is important to note that a complex having all the chemical
characteristics of a ligno-cellulose occurs in a soluble colloidal form
in the juice of the white currant. The formation of ligno-cellulose is
the chemical equiv