ved to have been broken, partially or entirely, but
more commonly to have been bruised and inflamed in its course under the
navicular or shuttle bone, or at its insertion into the bone of the foot.
Sometimes, although seldom, the navicular bone itself has been found to
have been fractured; at others its surface has been deprived of its usual
coating, and studded with projecting points or ridges of new growth, or
exhibiting superficial excavations more or less extensive.'[A]

[Footnote A: _Ibid_.]

_Pathology and Point of Commencement of the Disease_.--The exact position
in which the diseased process starts has for a long time been a subject
of discussion, and even now it is doubtful whether the point has been
definitely settled. To mention but a few among many: We find Mr. Broad, of
Bath, strenuously insisting on the fact that the disease commences in the
interior of the navicular bone. Just as strenuously we find the editor of
the journal in which the matter is being discussed, the late Mr. Fleming,
asserting that the disease commences in the bursa.[A] Others, too, hold
that the disease commences primarily in the tendon. Wedded to this view was
the discoverer, Mr. Turner, of Croydon; while Percival commits himself to
the statement that it is either the central ridge or the postero-inferior
surface of the navicular bone, or the opposed concavity in the perforans
tendon, that shows the earliest signs of the disease. The observations made
by Dr. Brauell, the first Continental writer to fully describe the disease,
led him to the statement that neither the bone nor the bursa was the
_invariable_ starting-point of the trouble, but that usually it commenced
in inflammation of the bursa itself.

[Footnote A: Percival's 'Hippopathology,' vol. iv., p. 132.]

Without, therefore, committing ourselves to an expression of opinion as
to the precise starting-point of the affection, we shall describe the
pathological changes occurring in navicular disease as noted in (1) the
bursa, (2) the cartilage, (3) the tendon, and (4) the bone.

1. _Changes in the Bursa_.--Upon the internal surface of the bursal
membrane is first noticed a slight inflammatory hyperaemia, accompanied
by more or less swelling and tumefaction, owing to its infiltration with
inflammatory exudate. The portion covering the hyaline cartilage of the
navicular bone has lost its peculiar pearl-blue shimmer, and become a dirty
yellow.

Remembering that the bursal membr