These Glands, as described by Dr. _Havers_ in his new Osteology, and as
they discover themselves upon Dissection, are of two Kinds; some are
small and thickly interspersed in the Membranes of the Joints, and with
very few Exceptions of an equal Bigness, so as to render the Membrane
perfectly Glandulous: In some Parts of the Membrane, in the Joints, and
in the Furrows of the Bone, these Glands are so united as to form very
remarkable and large conglomerate Glands. In some of the large Joints
there is but one, as in the Hip Joint; in others, as in the Knee, four
or five; they are of a red Colour, which is communicated from the blood
Vessels; as to their Substance, soft and papillary, tho’ not tender
and friable; they are in their Structure Conglomerate, consisting of
divers Membranes, wove one within another, interspersed with small
round Vesicles, which are not only contiguous, but adhere closely one
to another, as the Membranes also do. By the Pores of these little
Vesicles a mucilaginous Liquor is strained and secerned from the
general Mass of the arterial Blood, and thence by the excretory Duct,
with which all these Glands are furnished, is shed into the Interstices
of all the Joints.